function where(collection, source) {
      return filter(collection, matches(source));
    }
Performs a deep comparison between each element in `collection` and the
source object, returning an array of all elements that have equivalent
property values.

@static
@memberOf _
@category Collection
@param {Array|Object|string} collection The collection to search.
@param {Object} source The object of property values to match.
@returns {Array} Returns the new filtered array.
@example

var users = [
  { 'user': 'barney', 'age': 36, 'status': 'busy', 'pets': ['hoppy'] },
  { 'user': 'fred',   'age': 40, 'status': 'busy', 'pets': ['baby puss', 'dino'] }
];

_.pluck(_.where(users, { 'age': 36 }), 'user');
// => ['barney']

_.pluck(_.where(users, { 'pets': ['dino'] }), 'user');
// => ['fred']

_.pluck(_.where(users, { 'status': 'busy' }), 'user');
// => ['barney', 'fred']