function MVTSource(source, sources) {
    var _this;
    _classCallCheck(this, MVTSource);
    _this = _callSuper$2(this, MVTSource, [source, sources]);
    _this.response_type = 'arraybuffer'; // binary data

    // Optionally parse some or all properties from JSON strings
    if (source.parse_json === true) {
      // try to parse all properties (least efficient)
      _this.parse_json_type = PARSE_JSON_TYPE.ALL;
    } else if (Array.isArray(source.parse_json)) {
      // try to parse a specific list of property names (more efficient)
      _this.parse_json_type = PARSE_JSON_TYPE.SOME;
      _this.parse_json_prop_list = source.parse_json;
    } else {
      if (source.parse_json != null) {
        var msg = "Data source '".concat(_this.name, "': 'parse_json' parameter should be 'true', or an array of ") + "property names (was '".concat(JSON.stringify(source.parse_json), "')");
        log({
          level: 'warn',
          once: true
        }, msg);
      }

      // skip parsing entirely (default behavior)
      _this.parse_json_type = PARSE_JSON_TYPE.NONE;
    }
    return _this;
  }
Mapbox Vector Tile format
 @class MVTSource