if clientGone {
			// TODO: could we also get into this state if
			// the peer does a half close
			// (e.g. CloseWrite) because they're done
			// sending frames but they're still wanting
			// our open replies?  Investigate.
			// TODO: add CloseWrite to crypto/tls.Conn first
			// so we have a way to test this? I suppose
			// just for testing we could have a non-TLS mode.
			return false

// and always returns nil.
func (r *RingBuffer) CloseWithError(err error) {
	if err == nil {
		err = io.EOF
	}
	r.setErr(err, false)
}

// CloseWriter closes the writer.
// Reads will return any remaining bytes and io.EOF.
func (r *RingBuffer) CloseWriter() {
	r.setErr(io.EOF, false)
}

// Flush waits for the buffer to be empty and fully read.

			}
			if doSleep && writeRng.Intn(10) == 0 {
				time.Sleep(time.Duration(writeRng.Intn(maxSleep)))
			}
		}
		if err := rb.Flush(); err != nil {
			t.Fatalf("flush failed: %v", err)
		}
		rb.CloseWriter()
	}
	wg.Wait()
	if !errors.Is(readErr, io.EOF) {
		t.Fatalf("expect io.EOF but got %v", readErr)
	}
	if readBytes != wroteBytes {
		a, b := readBuf.Bytes(), wroteBuf.Bytes()

pkg net, method (*UDPConn) WriteMsgUDP([]uint8, []uint8, *UDPAddr) (int, int, error)
pkg net, method (*UnixConn) CloseRead() error
pkg net, method (*UnixConn) CloseWrite() error
pkg net, type Dialer struct
pkg net, type Dialer struct, Deadline time.Time
pkg net, type Dialer struct, LocalAddr Addr
pkg net, type Dialer struct, Timeout time.Duration