unassign method
Implementation
ISocket? unassign() {
if (_sock != null) {
// connected = false;
// _sock.off("close", socket_OnClose);
// _sock.off("connect", socket_OnConnect);
// _sock.off("receive", socket_OnReceive);
_sock?.receiver = null;
var rt = _sock;
_sock = null;
return rt;
} else
return null;
}