public function array_map_deep( $callback, $data ) {
		$results =	array();
		$args = array();
		if ( func_num_args() > 2 ) {
			$args =	(array) array_shift( array_slice( func_get_args(), 2 ) );
		}

		foreach ( $data as $key => $value ) {
			if ( is_array( $value ) ) {
				array_unshift( $args, $value );
				array_unshift( $args, $callback );
				$results[ $key ] = call_user_func_array( array( 'self', 'array_map_deep' ), $args );
			}
			else {
				array_unshift( $args, $value );
				$results[ $key ] = call_user_func_array( $callback, $args );
			}
		}
		return $results;
	}