protected function _getValueFromArray( $config, $parts )
	{
		if( ( $key = array_shift( $parts ) ) !== null && isset( $config[$key] ) )
		{
			if( count( $parts ) > 0 ) {
				return $this->_getValueFromArray( $config[$key], $parts );
			}

			return $config[$key];
		}

		return null;
	}