code: public function encodeGeoPoint(GeoPoint $geoPoint, Field $field)
      {
          return [
              'M' => [
                  'type'        => [self::TYPE_STRING => 'Point'],
                  'coordinates' => [
                      'L' => [
                          [self::TYPE_NUMBER => (string)$geoPoint->getLongitude()],
                          [self::TYPE_NUMBER => (string)$geoPoint->getLatitude()],
                      ],
                  ],
              ],
          ];
      }
docs: @param GeoPoint $geoPoint
  @param Field    $field
  
  @return mixed