GoogleMaps\Parameters::getQueryString PHP Method

    public static function getQueryString(&$param)
    {
        // Geocoding components parameter
        if (isset($param['components']) && is_array($param['components'])) {
            $param['components'] = self::joinParam($param['components'], ':', '|');
        }
        ///
        // Direction parameters
        if (isset($param['origin']) && is_array($param['origin'])) {
            $param['origin'] = self::joinParam($param['origin'], '', ':', false);
        }
        if (isset($param['destination']) && is_array($param['destination'])) {
            $param['destination'] = self::joinParam($param['destination'], '', ':', false);
        }
        if (isset($param['waypoints']) && is_array($param['waypoints'])) {
            $param['waypoints'] = self::joinParam($param['waypoints'], '', '|', false);
        }
        if (isset($param['avoid']) && is_array($param['avoid'])) {
            $param['avoid'] = self::joinParam($param['avoid'], '', '|', false);
        }
        ///
        // Distance Matrix parameters
        if (isset($param['origins']) && is_array($param['origins'])) {
            $param['origins'] = self::joinParam($param['origins'], '', '|', false);
        }
        if (isset($param['destinations']) && is_array($param['destinations'])) {
            $param['destinations'] = self::joinParam($param['destinations'], '', '|', false);
        }
        if (isset($param['transit_mode']) && is_array($param['transit_mode'])) {
            $param['transit_mode'] = self::joinParam($param['transit_mode'], '', '|', false);
        }
        ///
        // Elevation & Road parameters
        if (isset($param['locations']) && is_array($param['locations'])) {
            $param['locations'] = self::joinParam($param['locations'], '', '|', false);
        }
        if (isset($param['path']) && is_array($param['path'])) {
            $param['path'] = self::joinParam($param['path'], '', '|', false);
        }
        ///
        // Places & Time Zone parameters
        if (isset($param['location']) && is_array($param['location'])) {
            $param['location'] = self::joinParam($param['location'], '', ',', false);
        }
        /**
         * Place Search
         * Deprecation notices: Premium data (Zagat), types parameter, id and reference fields
         * Restricts the results to places matching the specified type. 
         * Only one type may be specified (if more than one type is provided, all types following the first entry are ignored).
         */
        if (isset($param['types']) && is_array($param['types'])) {
            #$param['types'] = self::joinParam( $param['types'], '', '|', false );
            $param['type'] = !empty($param['types'][0]) ? $param['types'][0] : "";
        }
        ///
        // reset to empty array
        self::$urlParam = [];
        return self::joinParam($param);
    }

 /**
  * Get Web Service Response
  * @return type
  */
 public function get()
 {
     // use output parameter if required by the service
     $this->requestUrl .= $this->service['endpoint'] ? $this->endpoint : '';
     // set API Key
     $this->requestUrl .= 'key=' . urlencode($this->key);
     // build query string
     $this->requestUrl .= '&' . Parameters::getQueryString($this->service['param']);
     return $this->service['decodePolyline'] ? $this->decode($this->make()) : $this->make();
 }