code: function FeedMessage(properties) {
              this.entity = [];
              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 FeedMessage.
  @memberof transit_realtime
  @interface IFeedMessage
  @property {transit_realtime.IFeedHeader} header FeedMessage header
  @property {Array.<transit_realtime.IFeedEntity>|null} [entity] FeedMessage entity
   
  Constructs a new FeedMessage.
  @memberof transit_realtime
  @classdesc Represents a FeedMessage.
  @implements IFeedMessage
  @constructor
  @param {transit_realtime.IFeedMessage=} [properties] Properties to set