Possible fix to FlightJS's on https://github.com/flightjs/flight/issues/260

fix-flight-off.js

this.off = function() {
  var $element, type, callback;
  var lastIndex = arguments.length - 1;
  var instanceInfo,
    origTypeRegex = '^(type)(?:\.(.+)|)$';

  if (typeof arguments[lastIndex] == 'function') {
    callback = arguments[lastIndex];
    lastIndex -= 1;
  }

  if (lastIndex == 1) {
    $element = $(arguments[0]);
    type = arguments[1];
  } else {
    $element = this.$node;
    type = arguments[0];
  }

  if (callback) {
    //this callback may be the original function or a bound version
    var boundFunctions = callback.target ? callback.target.bound : callback.bound || [];
    //set callback to version bound against this instance
    boundFunctions && boundFunctions.some(function(fn, i, arr) {
      if (fn.context && (this.identity == fn.context.identity)) {
        arr.splice(i, 1);
        callback = fn;
        return true;
      }
    }, this);

    $element.off(type, callback);
  } else {
    // Loop through the events of `this` instance
    // and unbind using the callback
    instanceInfo = registry.findInstanceInfo(this);

    if (instanceInfo) {
      origTypeRegex = new RegExp(origTypeRegex.replace('type', type), 'i');

      instanceInfo.events.forEach(function (event) {
        if (origTypeRegex.test(event.type)) {
          $element.off(type, event.callback);
        }
      });
    }
  }

  return $element;
};