protected bool _execCmdWaitFlag;  // wait response flag for sending exec command to server

        protected SSHConnection(SSHConnectionParameter param, AbstractGranadosSocket strm, ISSHConnectionEventReceiver receiver) {
            _param = (SSHConnectionParameter)param.Clone();
            _stream = strm;
            _eventReceiver = receiver;
            _channel_collection = new ChannelCollection();
            _autoDisconnect = true;
            _execCmd = null;
            _execCmdWaitFlag = true;
        }
        protected bool _execCmdWaitFlag;  // wait response flag for sending exec command to server

        protected SSHConnection(SSHConnectionParameter param, AbstractGranadosSocket strm, ISSHConnectionEventReceiver receiver)
        {
            _param              = (SSHConnectionParameter)param.Clone();
            _stream             = strm;
            _eventReceiver      = receiver;
            _channel_collection = new ChannelCollection();
            _autoDisconnect     = true;
            _execCmd            = null;
            _execCmdWaitFlag    = true;
        }