src/Storage/Collection.php
public function keyFilter($func) {
		
		$filtered = array_filter($this->keys(), $func);
		
		return new static(array_intersect_key($this->_data, array_flip($filtered)));
	}
public function keyFilter($func) {
		
		$filtered = array_filter($this->keys(), $func);
		
		return new static(array_intersect_key($this->_data, array_flip($filtered)));
	}
public function keyFilter ( $ func ) { $ filtered = array_filter ( $ this -> keys ( ) , $ func ) ; return new static ( array_intersect_key ( $ this -> _data , array_flip ( $ filtered ) ) ) ; }
Filters the items by key and returns a new collection.

@param callable $func
@return \xpl\Common\Storage\Collection
Filters the items by key and returns a new collection .