code: function filter(collection, predicate) {
        var func = isArray(collection) ? arrayFilter : baseFilter;
        return func(collection, getIteratee(predicate, 3));
      }
docs: Iterates over elements of `collection`, returning an array of all elements
  `predicate` returns truthy for. The predicate is invoked with three
  arguments: (value, index|key, collection).
  
  **Note:** Unlike `_.remove`, this method returns a new array.
  
  @static
  @memberOf _
  @since 0.1.0
  @category Collection
  @param {Array|Object} collection The collection to iterate over.
  @param {Function} [predicate=_.identity] The function invoked per iteration.
  @returns {Array} Returns the new filtered array.
  @see _.reject
  @example
  
  var users = [
  { 'user': 'barney', 'age': 36, 'active': true },
  { 'user': 'fred',   'age': 40, 'active': false }
  ];
  
  _.filter(users, function(o) { return !o.active; });
  // => objects for ['fred']
  
  // The `_.matches` iteratee shorthand.
  _.filter(users, { 'age': 36, 'active': true });
  // => objects for ['barney']
  
  // The `_.matchesProperty` iteratee shorthand.
  _.filter(users, ['active', false]);
  // => objects for ['fred']
  
  // The `_.property` iteratee shorthand.
  _.filter(users, 'active');
  // => objects for ['barney']