public UpdateHostHeartbeatCommand(IHeartbeatCommand heartbeatCommand)
        {
            if (heartbeatCommand == null)
            {
                throw new ArgumentNullException("heartbeatCommand");
            }

            _heartbeatCommand = heartbeatCommand;
        }
        public UpdateHostHeartbeatCommand(IHeartbeatCommand heartbeatCommand)
        {
            if (heartbeatCommand == null)
            {
                throw new ArgumentNullException("heartbeatCommand");
            }

            _heartbeatCommand = heartbeatCommand;
        }