dispose method
void
dispose()
Implementation
void dispose() {
if (_disposed) return;
_disposed = true;
_client?.dispose();
_grid.dispose();
_title.dispose();
_outputCtl.close();
_bellCtl.close();
_clipboardCtl.close();
_clipboardLoadCtl.close();
_notifyCtl.close();
_workingDir.dispose();
}