code: function PacketHeartbeat(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 PacketHeartbeat.
  @memberof packets
  @interface IPacketHeartbeat
  @property {string} ver PacketHeartbeat ver
  @property {string} sender PacketHeartbeat sender
  @property {number} cpu PacketHeartbeat cpu
   
  Constructs a new PacketHeartbeat.
  @memberof packets
  @classdesc Represents a PacketHeartbeat.
  @implements IPacketHeartbeat
  @constructor
  @param {packets.IPacketHeartbeat=} [properties] Properties to set