Add .filter to JavaScript objects.

object-filter.js

// Based on: http://stackoverflow.com/a/5072145/12815
Object.filter = function(obj, predicate) {
  var result = {}, key;
  for(key in obj) {
    if (obj.hasOwnProperty(key) && predicate.call(obj, key, obj[key])) {
      result[key] = obj[key];
    }//end if: key added to result
  }//end for: iterated over the object

  return result;
};