code: func DisableEcho(fd uintptr, state *State) error {
  	mode := state.mode
  	mode &^= winterm.ENABLE_ECHO_INPUT
  	mode |= winterm.ENABLE_PROCESSED_INPUT | winterm.ENABLE_LINE_INPUT
  	err := winterm.SetConsoleMode(fd, mode)
  	if err != nil {
  		return err
  	}
  
  	// Register an interrupt handler to catch and restore prior state
  	restoreAtInterrupt(fd, state)
  	return nil
  }
docs: // DisableEcho disables echo for the terminal connected to the given file descriptor.
  // -- See https://msdn.microsoft.com/en-us/library/windows/desktop/ms683462(v=vs.85).aspx