function ProtocolMessage(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]];
            }
Constructs a new ProtocolMessage.
@memberof proto.Message
@classdesc Represents a ProtocolMessage.
@implements IProtocolMessage
@constructor
@param {proto.Message.IProtocolMessage=} [properties] Properties to set