Make Apple Music work again on TenFourFox/IWPPC

gistfile1.txt

// ==UserScript==
// @name        Apple Music
// @namespace   https://music.apple.com/*
// @include     https://music.apple.com/*
// @run-at      document-start
// @version     1
// @grant       none
// ==/UserScript==
/**
 * Copyright 2016 Google Inc. All Rights Reserved.
 *
 * Licensed under the W3C SOFTWARE AND DOCUMENT NOTICE AND LICENSE.
 *
 *  https://www.w3.org/Consortium/Legal/2015/copyright-software-and-document
 *
 */
(function () {
  'use strict';
  // Exit early if we're not running in a browser.
  if (typeof window !== 'object') {
    return;
  }
  // Exit early if all IntersectionObserver and IntersectionObserverEntry
  // features are natively supported.

  if ('IntersectionObserver' in window &&
  'IntersectionObserverEntry' in window &&
  'intersectionRatio' in window.IntersectionObserverEntry.prototype) {
    // Minimal polyfill for Edge 15's lack of `isIntersecting`
    // See: https://github.com/w3c/IntersectionObserver/issues/211
    if (!('isIntersecting' in window.IntersectionObserverEntry.prototype)) {
      Object.defineProperty(window.IntersectionObserverEntry.prototype, 'isIntersecting', {
        get: function () {
          return this.intersectionRatio > 0;
        }
      });
    }
    return;
  }
  /**
 * Returns the embedding frame element, if any.
 * @param {!Document} doc
 * @return {!Element}
 */

  function getFrameElement(doc) {
    try {
      return doc.defaultView && doc.defaultView.frameElement || null;
    } catch (e) {
      // Ignore the error.
      return null;
    }
  }
  /**
 * A local reference to the root document.
 */

  var document = (function (startDoc) {
    var doc = startDoc;
    var frame = getFrameElement(doc);
    while (frame) {
      doc = frame.ownerDocument;
      frame = getFrameElement(doc);
    }
    return doc;
  }) (window.document);
  /**
 * An IntersectionObserver registry. This registry exists to hold a strong
 * reference to IntersectionObserver instances currently observing a target
 * element. Without this registry, instances without another reference may be
 * garbage collected.
 */
  var registry = [
  ];
  /**
 * The signal updater for cross-origin intersection. When not null, it means
 * that the polyfill is configured to work in a cross-origin mode.
 * @type {function(DOMRect|ClientRect, DOMRect|ClientRect)}
 */
  var crossOriginUpdater = null;
  /**
 * The current cross-origin intersection. Only used in the cross-origin mode.
 * @type {DOMRect|ClientRect}
 */
  var crossOriginRect = null;
  /**
 * Creates the global IntersectionObserverEntry constructor.
 * https://w3c.github.io/IntersectionObserver/#intersection-observer-entry
 * @param {Object} entry A dictionary of instance properties.
 * @constructor
 */
  function IntersectionObserverEntry(entry) {
    this.time = entry.time;
    this.target = entry.target;
    this.rootBounds = ensureDOMRect(entry.rootBounds);
    this.boundingClientRect = ensureDOMRect(entry.boundingClientRect);
    this.intersectionRect = ensureDOMRect(entry.intersectionRect || getEmptyRect());
    this.isIntersecting = !!entry.intersectionRect;
    // Calculates the intersection ratio.
    var targetRect = this.boundingClientRect;
    var targetArea = targetRect.width * targetRect.height;
    var intersectionRect = this.intersectionRect;
    var intersectionArea = intersectionRect.width * intersectionRect.height;
    // Sets intersection ratio.
    if (targetArea) {
      // Round the intersection ratio to avoid floating point math issues:
      // https://github.com/w3c/IntersectionObserver/issues/324
      this.intersectionRatio = Number((intersectionArea / targetArea).toFixed(4));
    } else {
      // If area is zero and is intersecting, sets to 1, otherwise to 0
      this.intersectionRatio = this.isIntersecting ? 1 : 0;
    }
  }
  /**
 * Creates the global IntersectionObserver constructor.
 * https://w3c.github.io/IntersectionObserver/#intersection-observer-interface
 * @param {Function} callback The function to be invoked after intersection
 *     changes have queued. The function is not invoked if the queue has
 *     been emptied by calling the `takeRecords` method.
 * @param {Object=} opt_options Optional configuration options.
 * @constructor
 */

  function IntersectionObserver(callback, opt_options) {
    var options = opt_options || {
    };
    if (typeof callback != 'function') {
      throw new Error('callback must be a function');
    }
    if (options.root &&
    options.root.nodeType != 1 &&
    options.root.nodeType != 9
    ) {
      throw new Error('root must be a Document or Element');
    }
    // Binds and throttles `this._checkForIntersections`.

    this._checkForIntersections = throttle(this._checkForIntersections.bind(this), this.THROTTLE_TIMEOUT);
    // Private properties.
    this._callback = callback;
    this._observationTargets = [
    ];
    this._queuedEntries = [
    ];
    this._rootMarginValues = this._parseRootMargin(options.rootMargin);
    // Public properties.
    this.thresholds = this._initThresholds(options.threshold);
    this.root = options.root || null;
    this.rootMargin = this._rootMarginValues.map(function (margin) {
      return margin.value + margin.unit;
    }).join(' ');
    /** @private @const {!Array<!Document>} */
    this._monitoringDocuments = [
    ];
    /** @private @const {!Array<function()>} */
    this._monitoringUnsubscribes = [
    ];
  }
  /**
 * The minimum interval within which the document will be checked for
 * intersection changes.
 */

  IntersectionObserver.prototype.THROTTLE_TIMEOUT = 100;
  /**
 * The frequency in which the polyfill polls for intersection changes.
 * this can be updated on a per instance basis and must be set prior to
 * calling `observe` on the first target.
 */
  IntersectionObserver.prototype.POLL_INTERVAL = null;
  /**
 * Use a mutation observer on the root element
 * to detect intersection changes.
 */
  IntersectionObserver.prototype.USE_MUTATION_OBSERVER = true;
  /**
 * Sets up the polyfill in the cross-origin mode. The result is the
 * updater function that accepts two arguments: `boundingClientRect` and
 * `intersectionRect` - just as these fields would be available to the
 * parent via `IntersectionObserverEntry`. This function should be called
 * each time the iframe receives intersection information from the parent
 * window, e.g. via messaging.
 * @return {function(DOMRect|ClientRect, DOMRect|ClientRect)}
 */
  IntersectionObserver._setupCrossOriginUpdater = function () {
    if (!crossOriginUpdater) {
      /**
     * @param {DOMRect|ClientRect} boundingClientRect
     * @param {DOMRect|ClientRect} intersectionRect
     */
      crossOriginUpdater = function (boundingClientRect, intersectionRect) {
        if (!boundingClientRect || !intersectionRect) {
          crossOriginRect = getEmptyRect();
        } else {
          crossOriginRect = convertFromParentRect(boundingClientRect, intersectionRect);
        }
        registry.forEach(function (observer) {
          observer._checkForIntersections();
        });
      };
    }
    return crossOriginUpdater;
  };
  /**
 * Resets the cross-origin mode.
 */
  IntersectionObserver._resetCrossOriginUpdater = function () {
    crossOriginUpdater = null;
    crossOriginRect = null;
  };
  /**
 * Starts observing a target element for intersection changes based on
 * the thresholds values.
 * @param {Element} target The DOM element to observe.
 */
  IntersectionObserver.prototype.observe = function (target) {
    var isTargetAlreadyObserved = this._observationTargets.some(function (item) {
      return item.element == target;
    });
    if (isTargetAlreadyObserved) {
      return;
    }
    if (!(target && target.nodeType == 1)) {
      throw new Error('target must be an Element');
    }
    this._registerInstance();
    this._observationTargets.push({
      element: target,
      entry: null
    });
    this._monitorIntersections(target.ownerDocument);
    this._checkForIntersections();
  };
  /**
 * Stops observing a target element for intersection changes.
 * @param {Element} target The DOM element to observe.
 */
  IntersectionObserver.prototype.unobserve = function (target) {
    this._observationTargets =
    this._observationTargets.filter(function (item) {
      return item.element != target;
    });
    this._unmonitorIntersections(target.ownerDocument);
    if (this._observationTargets.length == 0) {
      this._unregisterInstance();
    }
  };
  /**
 * Stops observing all target elements for intersection changes.
 */
  IntersectionObserver.prototype.disconnect = function () {
    this._observationTargets = [
    ];
    this._unmonitorAllIntersections();
    this._unregisterInstance();
  };
  /**
 * Returns any queue entries that have not yet been reported to the
 * callback and clears the queue. This can be used in conjunction with the
 * callback to obtain the absolute most up-to-date intersection information.
 * @return {Array} The currently queued entries.
 */
  IntersectionObserver.prototype.takeRecords = function () {
    var records = this._queuedEntries.slice();
    this._queuedEntries = [
    ];
    return records;
  };
  /**
 * Accepts the threshold value from the user configuration object and
 * returns a sorted array of unique threshold values. If a value is not
 * between 0 and 1 and error is thrown.
 * @private
 * @param {Array|number=} opt_threshold An optional threshold value or
 *     a list of threshold values, defaulting to [0].
 * @return {Array} A sorted list of unique and valid threshold values.
 */
  IntersectionObserver.prototype._initThresholds = function (opt_threshold) {
    var threshold = opt_threshold || [0];
    if (!Array.isArray(threshold)) threshold = [
      threshold
    ];
    return threshold.sort().filter(function (t, i, a) {
      if (typeof t != 'number' || isNaN(t) || t < 0 || t > 1) {
        throw new Error('threshold must be a number between 0 and 1 inclusively');
      }
      return t !== a[i - 1];
    });
  };
  /**
 * Accepts the rootMargin value from the user configuration object
 * and returns an array of the four margin values as an object containing
 * the value and unit properties. If any of the values are not properly
 * formatted or use a unit other than px or %, and error is thrown.
 * @private
 * @param {string=} opt_rootMargin An optional rootMargin value,
 *     defaulting to '0px'.
 * @return {Array<Object>} An array of margin objects with the keys
 *     value and unit.
 */
  IntersectionObserver.prototype._parseRootMargin = function (opt_rootMargin) {
    var marginString = opt_rootMargin || '0px';
    var margins = marginString.split(/\s+/).map(function (margin) {
      var parts = /^(-?\d*\.?\d+)(px|%)$/.exec(margin);
      if (!parts) {
        throw new Error('rootMargin must be specified in pixels or percent');
      }
      return {
        value: parseFloat(parts[1]),
        unit: parts[2]
      };
    });
    // Handles shorthand.
    margins[1] = margins[1] || margins[0];
    margins[2] = margins[2] || margins[0];
    margins[3] = margins[3] || margins[1];
    return margins;
  };
  /**
 * Starts polling for intersection changes if the polling is not already
 * happening, and if the page's visibility state is visible.
 * @param {!Document} doc
 * @private
 */
  IntersectionObserver.prototype._monitorIntersections = function (doc) {
    var win = doc.defaultView;
    if (!win) {
      // Already destroyed.
      return;
    }
    if (this._monitoringDocuments.indexOf(doc) != - 1) {
      // Already monitoring.
      return;
    }
    // Private state for monitoring.

    var callback = this._checkForIntersections;
    var monitoringInterval = null;
    var domObserver = null;
    // If a poll interval is set, use polling instead of listening to
    // resize and scroll events or DOM mutations.
    if (this.POLL_INTERVAL) {
      monitoringInterval = win.setInterval(callback, this.POLL_INTERVAL);
    } else {
      addEvent(win, 'resize', callback, true);
      addEvent(doc, 'scroll', callback, true);
      if (this.USE_MUTATION_OBSERVER && 'MutationObserver' in win) {
        domObserver = new win.MutationObserver(callback);
        domObserver.observe(doc, {
          attributes: true,
          childList: true,
          characterData: true,
          subtree: true
        });
      }
    }
    this._monitoringDocuments.push(doc);
    this._monitoringUnsubscribes.push(function () {
      // Get the window object again. When a friendly iframe is destroyed, it
      // will be null.
      var win = doc.defaultView;
      if (win) {
        if (monitoringInterval) {
          win.clearInterval(monitoringInterval);
        }
        removeEvent(win, 'resize', callback, true);
      }
      removeEvent(doc, 'scroll', callback, true);
      if (domObserver) {
        domObserver.disconnect();
      }
    });
    // Also monitor the parent.
    var rootDoc = (this.root && (this.root.ownerDocument || this.root)) || document;
    if (doc != rootDoc) {
      var frame = getFrameElement(doc);
      if (frame) {
        this._monitorIntersections(frame.ownerDocument);
      }
    }
  };
  /**
 * Stops polling for intersection changes.
 * @param {!Document} doc
 * @private
 */
  IntersectionObserver.prototype._unmonitorIntersections = function (doc) {
    var index = this._monitoringDocuments.indexOf(doc);
    if (index == - 1) {
      return;
    }
    var rootDoc = (this.root && (this.root.ownerDocument || this.root)) || document;
    // Check if any dependent targets are still remaining.
    var hasDependentTargets =
    this._observationTargets.some(function (item) {
      var itemDoc = item.element.ownerDocument;
      // Target is in this context.
      if (itemDoc == doc) {
        return true;
      }
      // Target is nested in this context.

      while (itemDoc && itemDoc != rootDoc) {
        var frame = getFrameElement(itemDoc);
        itemDoc = frame && frame.ownerDocument;
        if (itemDoc == doc) {
          return true;
        }
      }
      return false;
    });
    if (hasDependentTargets) {
      return;
    }
    // Unsubscribe.

    var unsubscribe = this._monitoringUnsubscribes[index];
    this._monitoringDocuments.splice(index, 1);
    this._monitoringUnsubscribes.splice(index, 1);
    unsubscribe();
    // Also unmonitor the parent.
    if (doc != rootDoc) {
      var frame = getFrameElement(doc);
      if (frame) {
        this._unmonitorIntersections(frame.ownerDocument);
      }
    }
  };
  /**
 * Stops polling for intersection changes.
 * @param {!Document} doc
 * @private
 */
  IntersectionObserver.prototype._unmonitorAllIntersections = function () {
    var unsubscribes = this._monitoringUnsubscribes.slice(0);
    this._monitoringDocuments.length = 0;
    this._monitoringUnsubscribes.length = 0;
    for (var i = 0; i < unsubscribes.length; i++) {
      unsubscribes[i]();
    }
  };
  /**
 * Scans each observation target for intersection changes and adds them
 * to the internal entries queue. If new entries are found, it
 * schedules the callback to be invoked.
 * @private
 */
  IntersectionObserver.prototype._checkForIntersections = function () {
    if (!this.root && crossOriginUpdater && !crossOriginRect) {
      // Cross origin monitoring, but no initial data available yet.
      return;
    }
    var rootIsInDom = this._rootIsInDom();
    var rootRect = rootIsInDom ? this._getRootRect()  : getEmptyRect();
    this._observationTargets.forEach(function (item) {
      var target = item.element;
      var targetRect = getBoundingClientRect(target);
      var rootContainsTarget = this._rootContainsTarget(target);
      var oldEntry = item.entry;
      var intersectionRect = rootIsInDom && rootContainsTarget &&
      this._computeTargetAndRootIntersection(target, targetRect, rootRect);
      var rootBounds = null;
      if (!this._rootContainsTarget(target)) {
        rootBounds = getEmptyRect();
      } else if (!crossOriginUpdater || this.root) {
        rootBounds = rootRect;
      }
      var newEntry = item.entry = new IntersectionObserverEntry({
        time: now(),
        target: target,
        boundingClientRect: targetRect,
        rootBounds: rootBounds,
        intersectionRect: intersectionRect
      });
      if (!oldEntry) {
        this._queuedEntries.push(newEntry);
      } else if (rootIsInDom && rootContainsTarget) {
        // If the new entry intersection ratio has crossed any of the
        // thresholds, add a new entry.
        if (this._hasCrossedThreshold(oldEntry, newEntry)) {
          this._queuedEntries.push(newEntry);
        }
      } else {
        // If the root is not in the DOM or target is not contained within
        // root but the previous entry for this target had an intersection,
        // add a new record indicating removal.
        if (oldEntry && oldEntry.isIntersecting) {
          this._queuedEntries.push(newEntry);
        }
      }
    }, this);
    if (this._queuedEntries.length) {
      this._callback(this.takeRecords(), this);
    }
  };
  /**
 * Accepts a target and root rect computes the intersection between then
 * following the algorithm in the spec.
 * TODO(philipwalton): at this time clip-path is not considered.
 * https://w3c.github.io/IntersectionObserver/#calculate-intersection-rect-algo
 * @param {Element} target The target DOM element
 * @param {Object} targetRect The bounding rect of the target.
 * @param {Object} rootRect The bounding rect of the root after being
 *     expanded by the rootMargin value.
 * @return {?Object} The final intersection rect object or undefined if no
 *     intersection is found.
 * @private
 */
  IntersectionObserver.prototype._computeTargetAndRootIntersection =
  function (target, targetRect, rootRect) {
    // If the element isn't displayed, an intersection can't happen.
    if (window.getComputedStyle(target).display == 'none') return;
    var intersectionRect = targetRect;
    var parent = getParentNode(target);
    var atRoot = false;
    while (!atRoot && parent) {
      var parentRect = null;
      var parentComputedStyle = parent.nodeType == 1 ?
      window.getComputedStyle(parent)  : {
      };
      // If the parent isn't displayed, an intersection can't happen.
      if (parentComputedStyle.display == 'none') return null;
      if (parent == this.root || parent.nodeType == /* DOCUMENT */
      9) {
        atRoot = true;
        if (parent == this.root || parent == document) {
          if (crossOriginUpdater && !this.root) {
            if (!crossOriginRect ||
            crossOriginRect.width == 0 && crossOriginRect.height == 0) {
              // A 0-size cross-origin intersection means no-intersection.
              parent = null;
              parentRect = null;
              intersectionRect = null;
            } else {
              parentRect = crossOriginRect;
            }
          } else {
            parentRect = rootRect;
          }
        } else {
          // Check if there's a frame that can be navigated to.
          var frame = getParentNode(parent);
          var frameRect = frame && getBoundingClientRect(frame);
          var frameIntersect =
          frame &&
          this._computeTargetAndRootIntersection(frame, frameRect, rootRect);
          if (frameRect && frameIntersect) {
            parent = frame;
            parentRect = convertFromParentRect(frameRect, frameIntersect);
          } else {
            parent = null;
            intersectionRect = null;
          }
        }
      } else {
        // If the element has a non-visible overflow, and it's not the <body>
        // or <html> element, update the intersection rect.
        // Note: <body> and <html> cannot be clipped to a rect that's not also
        // the document rect, so no need to compute a new intersection.
        var doc = parent.ownerDocument;
        if (parent != doc.body &&
        parent != doc.documentElement &&
        parentComputedStyle.overflow != 'visible') {
          parentRect = getBoundingClientRect(parent);
        }
      }
      // If either of the above conditionals set a new parentRect,
      // calculate new intersection data.

      if (parentRect) {
        intersectionRect = computeRectIntersection(parentRect, intersectionRect);
      }
      if (!intersectionRect) break;
      parent = parent && getParentNode(parent);
    }
    return intersectionRect;
  };
  /**
 * Returns the root rect after being expanded by the rootMargin value.
 * @return {ClientRect} The expanded root rect.
 * @private
 */
  IntersectionObserver.prototype._getRootRect = function () {
    var rootRect;
    if (this.root && !isDoc(this.root)) {
      rootRect = getBoundingClientRect(this.root);
    } else {
      // Use <html>/<body> instead of window since scroll bars affect size.
      var doc = isDoc(this.root) ? this.root : document;
      var html = doc.documentElement;
      var body = doc.body;
      rootRect = {
        top: 0,
        left: 0,
        right: html.clientWidth || body.clientWidth,
        width: html.clientWidth || body.clientWidth,
        bottom: html.clientHeight || body.clientHeight,
        height: html.clientHeight || body.clientHeight
      };
    }
    return this._expandRectByRootMargin(rootRect);
  };
  /**
 * Accepts a rect and expands it by the rootMargin value.
 * @param {DOMRect|ClientRect} rect The rect object to expand.
 * @return {ClientRect} The expanded rect.
 * @private
 */
  IntersectionObserver.prototype._expandRectByRootMargin = function (rect) {
    var margins = this._rootMarginValues.map(function (margin, i) {
      return margin.unit == 'px' ? margin.value :
      margin.value * (i % 2 ? rect.width : rect.height) / 100;
    });
    var newRect = {
      top: rect.top - margins[0],
      right: rect.right + margins[1],
      bottom: rect.bottom + margins[2],
      left: rect.left - margins[3]
    };
    newRect.width = newRect.right - newRect.left;
    newRect.height = newRect.bottom - newRect.top;
    return newRect;
  };
  /**
 * Accepts an old and new entry and returns true if at least one of the
 * threshold values has been crossed.
 * @param {?IntersectionObserverEntry} oldEntry The previous entry for a
 *    particular target element or null if no previous entry exists.
 * @param {IntersectionObserverEntry} newEntry The current entry for a
 *    particular target element.
 * @return {boolean} Returns true if a any threshold has been crossed.
 * @private
 */
  IntersectionObserver.prototype._hasCrossedThreshold =
  function (oldEntry, newEntry) {
    // To make comparing easier, an entry that has a ratio of 0
    // but does not actually intersect is given a value of -1
    var oldRatio = oldEntry && oldEntry.isIntersecting ?
    oldEntry.intersectionRatio || 0 : - 1;
    var newRatio = newEntry.isIntersecting ?
    newEntry.intersectionRatio || 0 : - 1;
    // Ignore unchanged ratios
    if (oldRatio === newRatio) return;
    for (var i = 0; i < this.thresholds.length; i++) {
      var threshold = this.thresholds[i];
      // Return true if an entry matches a threshold or if the new ratio
      // and the old ratio are on the opposite sides of a threshold.
      if (threshold == oldRatio || threshold == newRatio ||
      threshold < oldRatio !== threshold < newRatio) {
        return true;
      }
    }
  };
  /**
 * Returns whether or not the root element is an element and is in the DOM.
 * @return {boolean} True if the root element is an element and is in the DOM.
 * @private
 */
  IntersectionObserver.prototype._rootIsInDom = function () {
    return !this.root || containsDeep(document, this.root);
  };
  /**
 * Returns whether or not the target element is a child of root.
 * @param {Element} target The target element to check.
 * @return {boolean} True if the target element is a child of root.
 * @private
 */
  IntersectionObserver.prototype._rootContainsTarget = function (target) {
    var rootDoc = (this.root && (this.root.ownerDocument || this.root)) || document;
    return (containsDeep(rootDoc, target) && (!this.root || rootDoc == target.ownerDocument)
    );
  };
  /**
 * Adds the instance to the global IntersectionObserver registry if it isn't
 * already present.
 * @private
 */
  IntersectionObserver.prototype._registerInstance = function () {
    if (registry.indexOf(this) < 0) {
      registry.push(this);
    }
  };
  /**
 * Removes the instance from the global IntersectionObserver registry.
 * @private
 */
  IntersectionObserver.prototype._unregisterInstance = function () {
    var index = registry.indexOf(this);
    if (index != - 1) registry.splice(index, 1);
  };
  /**
 * Returns the result of the performance.now() method or null in browsers
 * that don't support the API.
 * @return {number} The elapsed time since the page was requested.
 */
  function now() {
    return window.performance && performance.now && performance.now();
  }
  /**
 * Throttles a function and delays its execution, so it's only called at most
 * once within a given time period.
 * @param {Function} fn The function to throttle.
 * @param {number} timeout The amount of time that must pass before the
 *     function can be called again.
 * @return {Function} The throttled function.
 */

  function throttle(fn, timeout) {
    var timer = null;
    return function () {
      if (!timer) {
        timer = setTimeout(function () {
          fn();
          timer = null;
        }, timeout);
      }
    };
  }
  /**
 * Adds an event handler to a DOM node ensuring cross-browser compatibility.
 * @param {Node} node The DOM node to add the event handler to.
 * @param {string} event The event name.
 * @param {Function} fn The event handler to add.
 * @param {boolean} opt_useCapture Optionally adds the even to the capture
 *     phase. Note: this only works in modern browsers.
 */

  function addEvent(node, event, fn, opt_useCapture) {
    if (typeof node.addEventListener == 'function') {
      node.addEventListener(event, fn, opt_useCapture || false);
    } 
    else if (typeof node.attachEvent == 'function') {
      node.attachEvent('on' + event, fn);
    }
  }
  /**
 * Removes a previously added event handler from a DOM node.
 * @param {Node} node The DOM node to remove the event handler from.
 * @param {string} event The event name.
 * @param {Function} fn The event handler to remove.
 * @param {boolean} opt_useCapture If the event handler was added with this
 *     flag set to true, it should be set to true here in order to remove it.
 */

  function removeEvent(node, event, fn, opt_useCapture) {
    if (typeof node.removeEventListener == 'function') {
      node.removeEventListener(event, fn, opt_useCapture || false);
    } 
    else if (typeof node.detachEvent == 'function') {
      node.detachEvent('on' + event, fn);
    }
  }
  /**
 * Returns the intersection between two rect objects.
 * @param {Object} rect1 The first rect.
 * @param {Object} rect2 The second rect.
 * @return {?Object|?ClientRect} The intersection rect or undefined if no
 *     intersection is found.
 */

  function computeRectIntersection(rect1, rect2) {
    var top = Math.max(rect1.top, rect2.top);
    var bottom = Math.min(rect1.bottom, rect2.bottom);
    var left = Math.max(rect1.left, rect2.left);
    var right = Math.min(rect1.right, rect2.right);
    var width = right - left;
    var height = bottom - top;
    return (width >= 0 && height >= 0) && {
      top: top,
      bottom: bottom,
      left: left,
      right: right,
      width: width,
      height: height
    }
    || null;
  }
  /**
 * Shims the native getBoundingClientRect for compatibility with older IE.
 * @param {Element} el The element whose bounding rect to get.
 * @return {DOMRect|ClientRect} The (possibly shimmed) rect of the element.
 */

  function getBoundingClientRect(el) {
    var rect;
    try {
      rect = el.getBoundingClientRect();
    } catch (err) {
      // Ignore Windows 7 IE11 "Unspecified error"
      // https://github.com/w3c/IntersectionObserver/pull/205
    }
    if (!rect) return getEmptyRect();
    // Older IE
    if (!(rect.width && rect.height)) {
      rect = {
        top: rect.top,
        right: rect.right,
        bottom: rect.bottom,
        left: rect.left,
        width: rect.right - rect.left,
        height: rect.bottom - rect.top
      };
    }
    return rect;
  }
  /**
 * Returns an empty rect object. An empty rect is returned when an element
 * is not in the DOM.
 * @return {ClientRect} The empty rect.
 */

  function getEmptyRect() {
    return {
      top: 0,
      bottom: 0,
      left: 0,
      right: 0,
      width: 0,
      height: 0
    };
  }
  /**
 * Ensure that the result has all of the necessary fields of the DOMRect.
 * Specifically this ensures that `x` and `y` fields are set.
 *
 * @param {?DOMRect|?ClientRect} rect
 * @return {?DOMRect}
 */

  function ensureDOMRect(rect) {
    // A `DOMRect` object has `x` and `y` fields.
    if (!rect || 'x' in rect) {
      return rect;
    }
    // A IE's `ClientRect` type does not have `x` and `y`. The same is the case
    // for internally calculated Rect objects. For the purposes of
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    // for these fields.

    return {
      top: rect.top,
      y: rect.top,
      bottom: rect.bottom,
      left: rect.left,
      x: rect.left,
      right: rect.right,
      width: rect.width,
      height: rect.height
    };
  }
  /**
 * Inverts the intersection and bounding rect from the parent (frame) BCR to
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 * @param {DOMRect|ClientRect} parentBoundingRect The parent's bound client rect.
 * @param {DOMRect|ClientRect} parentIntersectionRect The parent's own intersection rect.
 * @return {ClientRect} The local root bounding rect for the parent's children.
 */

  function convertFromParentRect(parentBoundingRect, parentIntersectionRect) {
    var top = parentIntersectionRect.top - parentBoundingRect.top;
    var left = parentIntersectionRect.left - parentBoundingRect.left;
    return {
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      height: parentIntersectionRect.height,
      width: parentIntersectionRect.width,
      bottom: top + parentIntersectionRect.height,
      right: left + parentIntersectionRect.width
    };
  }
  /**
 * Checks to see if a parent element contains a child element (including inside
 * shadow DOM).
 * @param {Node} parent The parent element.
 * @param {Node} child The child element.
 * @return {boolean} True if the parent node contains the child node.
 */

  function containsDeep(parent, child) {
    var node = child;
    while (node) {
      if (node == parent) return true;
      node = getParentNode(node);
    }
    return false;
  }
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 * Gets the parent node of an element or its host element if the parent node
 * is a shadow root.
 * @param {Node} node The node whose parent to get.
 * @return {Node|null} The parent node or null if no parent exists.
 */

  function getParentNode(node) {
    var parent = node.parentNode;
    if (node.nodeType == /* DOCUMENT */
    9 && node != document) {
      // If this node is a document node, look for the embedding frame.
      return getFrameElement(node);
    }
    // If the parent has element that is assigned through shadow root slot

    if (parent && parent.assignedSlot) {
      parent = parent.assignedSlot.parentNode
    }
    if (parent && parent.nodeType == 11 && parent.host) {
      // If the parent is a shadow root, return the host element.
      return parent.host;
    }
    return parent;
  }
  /**
 * Returns true if `node` is a Document.
 * @param {!Node} node
 * @returns {boolean}
 */

  function isDoc(node) {
    return node && node.nodeType === 9;
  }
  // Exposes the constructors globally.

  window.IntersectionObserver = IntersectionObserver;
  window.IntersectionObserverEntry = IntersectionObserverEntry;
}());
/*! (c) Andrea Giammarchi @webreflection ISC */
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    return function (o, a) {
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          oldValue: null
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    return r
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    var r = 'undefined' != typeof Symbol && e[Symbol.iterator] || e['@@iterator'];
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        r && (e = r);
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        a = function () {
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        return {
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              done: !1,
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          e: function (e) {
            throw e
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          f: a
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      }
      throw new TypeError('Invalid attempt to iterate non-iterable instance.\nIn order to be iterable, non-array objects must have a [Symbol.iterator]() method.')
    }
    var l,
    i = !0,
    c = !1;
    return {
      s: function () {
        r = r.call(e)
      },
      n: function () {
        var e = r.next();
        return i = e.done,
        e
      },
      e: function (e) {
        c = !0,
        l = e
      },
      f: function () {
        try {
          i || null == r.return || r.return ()
        } finally {
          if (c) throw l
        }
      }
    }
  }
  /*! (c) Andrea Giammarchi - ISC */

  var r = !0,
  o = !1,
  a = 'querySelectorAll',
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  i = self,
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  u = i.Element,
  s = i.MutationObserver,
  f = i.Set,
  d = i.WeakMap,
  h = function (e) {
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      }(n), i = 0, c = y.length; i < c; i++) l.call(n, a = y[i]) && (t.has(n) || t.set(n, new f), (o = t.get(n)).has(a) || (o.add(a), e.handle(n, r, a)));
       else t.has(n) && (o = t.get(n), t.delete (n), o.forEach((function (t) {
        e.handle(n, r, t)
      })))
    },
    p = function (e) {
      for (var t = !(arguments.length > 1 && void 0 !== arguments[1]) || arguments[1], n = 0, r = e.length; n < r; n++) i(e[n], t)
    },
    y = e.query,
    g = e.root || c,
    m = function (e) {
      var t = arguments.length > 1 && void 0 !== arguments[1] ? arguments[1] : document,
      l = arguments.length > 2 && void 0 !== arguments[2] ? arguments[2] : MutationObserver,
      i = arguments.length > 3 && void 0 !== arguments[3] ? arguments[3] : [
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      c = function t(o, l, i, c, u, s) {
        var f,
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      drop: function (e) {
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      flush: function () {
        for (var e = m.takeRecords(), t = 0, n = e.length; t < n; t++) p(v.call(e[t].removedNodes, h), !1),
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  T = y.Reflect,
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  D = b.keys,
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  k = !self.customElements,
  L = function (e) {
    for (var t = D(e), n = [
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    var x = function () {
      var e = this.constructor;
      if (!$.has(e)) throw new C('Illegal constructor');
      var t = $.get(e);
      if (W) return F(W, t);
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    H = g.createElement,
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      get: function (e) {
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    q(x.prototype = M.prototype, 'constructor', {
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