protected function loadMapFromFile($location)
    {
        if (!file_exists($location)) {

            throw new Zend_Loader_Exception_InvalidArgumentException('Map file provided does not exist');
        }

        if (!$path = self::realPharPath($location)) {
            $path = realpath($location);
        }

        if (in_array($path, $this->mapsLoaded)) {
            // Already loaded this map
            return $this;
        }

        $map = include $path;

        return $map;
    }