.when(mockFlushable)
          .flush();
    }
  }

  // Flush the flushable using the Flushables, passing in the swallowException
  // parameter. expectThrown determines whether we expect an exception to
  // be thrown by Flushables.flush;
  private void doFlush(Flushable flushable, boolean swallowException, boolean expectThrown)
      throws IOException {
    try {
      Flushables.flush(flushable, swallowException);

  public Writer openStream() throws IOException {
    // using TestByteSink's output stream to get option behavior, so flush to it on every write
    return new FilterWriter(new OutputStreamWriter(byteSink.openStream(), UTF_8)) {
      @Override
      public void write(int c) throws IOException {
        super.write(c);
        flush();
      }

      @Override
      public void write(char[] cbuf, int off, int len) throws IOException {

      requestBody.flush()
      val responseBody = response.body.source()
      assertThat(responseBody.readUtf8Line())
        .isEqualTo("response B")
      requestBody.writeUtf8("request C\n")
      requestBody.flush()
      assertThat(responseBody.readUtf8Line())
        .isEqualTo("response D")
      requestBody.writeUtf8("request E\n")
      requestBody.flush()

            throw new IORuntimeException(e);
        }
    }

    /**
     * {@link OutputStream}をflushします。
     *
     * @param out
     *            出力ストリーム
     */
    public static void flush(final OutputStream out) {
        if (out == null) {
            return;
        }
        try {
            out.flush();
        } catch (final IOException e) {
            throw new IORuntimeException(e);
        }
    }

    super.write(c);
    flush(); // flush write to TestOutputStream to get its behavior
  }

  @Override
  public void write(char[] cbuf, int off, int len) throws IOException {
    super.write(cbuf, off, len);
    flush();
  }

  @Override
  public void write(String str, int off, int len) throws IOException {
    super.write(str, off, len);
    flush();
  }

  public boolean closed() {

          .when(mockFlushable)
          .flush();
    }
  }

  // Flush the flushable using the Flushables, passing in the swallowException
  // parameter. expectThrown determines whether we expect an exception to
  // be thrown by Flushables.flush;
  private void doFlush(Flushable flushable, boolean swallowException, boolean expectThrown)
      throws IOException {
    try {
      Flushables.flush(flushable, swallowException);

			if err != nil {
				return
			}
			if len(mergeCh) == 0 {
				// Flush if nothing is queued
				w.(http.Flusher).Flush()
			}
			grid.PutByteBuffer(ev)
		case <-emptyEventTicker:
			if err := enc.Encode(struct{ Records []event.Event }{}); err != nil {
				return
			}
			w.(http.Flusher).Flush()
		case <-keepAliveTicker:
			if _, err := w.Write([]byte(" ")); err != nil {
				return
			}

    if (byteCount > length) writeContinuationFrames(streamId, byteCount - length)
  }

  @Synchronized
  @Throws(IOException::class)
  fun flush() {
    if (closed) throw IOException("closed")
    sink.flush()
  }

  @Synchronized
  @Throws(IOException::class)
  fun rstStream(
    streamId: Int,
    errorCode: ErrorCode,
  ) {
    if (closed) throw IOException("closed")

   *     method
   * @throws IOException if {@code swallowIOException} is false and {@link Flushable#flush} throws
   *     an {@code IOException}.
   * @see Closeables#close
   */
  public static void flush(Flushable flushable, boolean swallowIOException) throws IOException {
    try {
      flushable.flush();
    } catch (IOException e) {
      if (swallowIOException) {

    super.write(c);
    flush(); // flush write to TestOutputStream to get its behavior
  }

  @Override
  public void write(char[] cbuf, int off, int len) throws IOException {
    super.write(cbuf, off, len);
    flush();
  }

  @Override
  public void write(String str, int off, int len) throws IOException {
    super.write(str, off, len);
    flush();
  }

  public boolean closed() {