?: throw ProtocolException("expected the Content-Type to have a boundary parameter"),
    )

    @Throws(IOException::class)
    fun nextPart(): Part? {
      check(!closed) { "closed" }

      if (noMoreParts) return null

      // Read a boundary, skipping the remainder of the preceding part as necessary.
      if (partCount == 0 && source.rangeEquals(0L, dashDashBoundary)) {

        add(newCloseables, directExecutor());
      }
    }

    @Override
    public void close() {
      if (closed) {
        return;
      }
      synchronized (this) {
        if (closed) {
          return;
        }
        closed = true;
      }
      for (Map.Entry<AutoCloseable, Executor> entry : entrySet()) {
        closeQuietly(entry.getKey(), entry.getValue());

import java.nio.charset.Charset;

/**
 * A destination to which bytes can be written, such as a file. Unlike an {@link OutputStream}, a
 * {@code ByteSink} is not an open, stateful stream that can be written to and closed. Instead, it
 * is an immutable <i>supplier</i> of {@code OutputStream} instances.
 *
 * <p>{@code ByteSink} provides two kinds of methods:
 *
 * <ul>

import java.nio.charset.Charset;

/**
 * A destination to which bytes can be written, such as a file. Unlike an {@link OutputStream}, a
 * {@code ByteSink} is not an open, stateful stream that can be written to and closed. Instead, it
 * is an immutable <i>supplier</i> of {@code OutputStream} instances.
 *
 * <p>{@code ByteSink} provides two kinds of methods:
 *
 * <ul>

  }

  public void testWriteFromStream_doesNotCloseThatStream() throws IOException {
    TestInputStream in = new TestInputStream(new ByteArrayInputStream(new byte[10]));
    assertFalse(in.closed());
    sink.writeFrom(in);
    assertFalse(in.closed());
  }

  public void testClosesOnErrors_copyingFromByteSourceThatThrows() {
    for (TestOption option : EnumSet.of(OPEN_THROWS, READ_THROWS, CLOSE_THROWS)) {

  }

  public void testWriteFromStream_doesNotCloseThatStream() throws IOException {
    TestInputStream in = new TestInputStream(new ByteArrayInputStream(new byte[10]));
    assertFalse(in.closed());
    sink.writeFrom(in);
    assertFalse(in.closed());
  }

  public void testClosesOnErrors_copyingFromByteSourceThatThrows() {
    for (TestOption option : EnumSet.of(OPEN_THROWS, READ_THROWS, CLOSE_THROWS)) {

    // from InputStream to OutputStream
    //
    /**
     * Copies from an input stream to an output stream.
     * <p>
     * Neither the input stream nor the output stream is closed.
     * </p>
     *
     * @param in the input stream (must not be {@literal null})
     * @param out the output stream (must not be {@literal null})
     * @return the number of bytes copied
     */

          val source = Buffer().writeUtf8("hello")
          return object : ForwardingSource(source) {
            override fun close() {
              closed = true
              super.close()
            }
          }.buffer()
        }
      }
    body.source().close()
    assertThat(closed).isTrue()
  }

  @Test
  fun throwingUnderlyingSourceClosesQuietly() {
    val body: ResponseBody =
      object : ResponseBody() {

   * most [BufferedSource] instances, but not of [Buffer].
   */
  private fun responseBody(content: String): ResponseBody {
    val data = Buffer().writeUtf8(content)
    val source: Source =
      object : Source {
        var closed = false

        override fun close() {
          closed = true
        }

        override fun read(

 *
 *  * **Closing:** one of the peers on the web socket has initiated a graceful shutdown. The web
 *    socket will continue to transmit already-enqueued messages but will refuse to enqueue new
 *    ones.
 *
 *  * **Closed:** the web socket has transmitted all of its messages and has received all messages
 *    from the peer.
 *
 * Web sockets may fail due to HTTP upgrade problems, connectivity problems, or if either peer