code: function VehicleDescriptor(properties) {
              if (properties)
                  for (var keys = Object.keys(properties), i = 0; i < keys.length; ++i)
                      if (properties[keys[i]] != null)
                          this[keys[i]] = properties[keys[i]];
          }
docs: Properties of a VehicleDescriptor.
  @memberof transit_realtime
  @interface IVehicleDescriptor
  @property {string|null} [id] VehicleDescriptor id
  @property {string|null} [label] VehicleDescriptor label
  @property {string|null} [licensePlate] VehicleDescriptor licensePlate
   
  Constructs a new VehicleDescriptor.
  @memberof transit_realtime
  @classdesc Represents a VehicleDescriptor.
  @implements IVehicleDescriptor
  @constructor
  @param {transit_realtime.IVehicleDescriptor=} [properties] Properties to set