protected function _merge( array $left, array $right )
	{
		foreach( $right as $key => $value )
		{
			if( isset( $left[$key] ) && is_array( $left[$key] ) && is_array( $value ) ) {
				$left[$key] = $this->_merge( $left[$key], $value );
			} else {
				$left[$key] = $value;
			}
		}

		return $left;
	}