public function getArray($key, callable $callback = null)
    {
        $list = $this->get($key);
        if (!is_array($list)) {
            return [];
        }
        if (is_callable($callback)) {
            return array_map($callback, $list);
        }
        return $list;
    }
public function getArray($key, callable $callback = null)
    {
        $list = $this->get($key);
        if (!is_array($list)) {
            return [];
        }
        if (is_callable($callback)) {
            return array_map($callback, $list);
        }
        return $list;
    }
public function getArray ( $ key , callable $ callback = null ) { $ list = $ this -> get ( $ key ) ; if ( ! is_array ( $ list ) ) { return [ ] ; } if ( is_callable ( $ callback ) ) { return array_map ( $ callback , $ list ) ; } return $ list ; }
Get a list item from collection with given key.
If item does not exist an empty array is returned.

@param string        $key
@param callable|null $callback Optional callable to map items in list

@return array
Get a list item from collection with given key . If item does not exist an empty array is returned .