lithium\util\Collection::each PHP Method

    public function each($filter)
    {
        $this->_data = array_map($filter, $this->_data);
        return $this;
    }

 public function schema()
 {
     $data = Libraries::locate('models');
     $models = new Collection(compact('data'));
     if ($this->request->is('json')) {
         $models->each(function ($model) {
             $schema = is_callable(array($model, 'schema')) ? $model::schema() : array();
             return array($model => $schema ? $schema->fields() : array());
         });
     }
     return compact('models');
 }