code: func NonBlockingWrite(fd int, buf []byte) *tcpip.Error {
  	var ptr unsafe.Pointer
  	if len(buf) > 0 {
  		ptr = unsafe.Pointer(&buf[0])
  	}
  
  	_, _, e := syscall.RawSyscall(syscall.SYS_WRITE, uintptr(fd), uintptr(ptr), uintptr(len(buf)))
  	if e != 0 {
  		return TranslateErrno(e)
  	}
  
  	return nil
  }
docs: // NonBlockingWrite writes the given buffer to a file descriptor. It fails if
  // partial data is written.