get() = if (limit == -1L) -1L else (limit - byteCount)

  fun hasNext(): Boolean = peekHeader() != null

  /**
   * Returns the next header to process unless this scope is exhausted.
   *
   * This returns null if:
   *
   *  * The stream is exhausted.
   *  * We've read all of the bytes of an object whose length is known.
   *  * We've reached the [DerHeader.TAG_END_OF_CONTENTS] of an object whose length is unknown.
   */

      UnmodifiableIterator<T> iterator) {
    return checkNotNull(iterator);
  }

  /**
   * Returns the number of elements remaining in {@code iterator}. The iterator will be left
   * exhausted: its {@code hasNext()} method will return {@code false}.
   */
  public static int size(Iterator<?> iterator) {
    long count = 0L;
    while (iterator.hasNext()) {
      iterator.next();
      count++;
    }

 * signatures.
 */
fun Buffer.isProbablyUtf8(): Boolean {
  try {
    val prefix = Buffer()
    val byteCount = size.coerceAtMost(64)
    copyTo(prefix, 0, byteCount)
    for (i in 0 until 16) {
      if (prefix.exhausted()) {
        break
      }
      val codePoint = prefix.readUtf8CodePoint()
      if (Character.isISOControl(codePoint) && !Character.isWhitespace(codePoint)) {
        return false
      }
    }
    return true

   * connection to an address fails, OkHttp will retry the connection with the next address until
   * either a connection is made, the set of IP addresses is exhausted, or a limit is exceeded.
   */
  @Throws(UnknownHostException::class)
  fun lookup(hostname: String): List<InetAddress>

  companion object {
    /**

  ) : SocketEffect

  /**
   * On HTTP/2, send a [GOAWAY frame](https://tools.ietf.org/html/rfc7540#section-6.8) immediately
   * after the response and will close the connection when the client's socket is exhausted.
   *
   * On HTTP/1 this closes the socket.
   */
  public object ShutdownConnection : SocketEffect

  /**
   * On HTTP/2 this will send the error code on the stream.
   *

 * returns the same bytes as the upstream source. Downstream sources may read data either as it
 * is returned by upstream, or after the upstream source has been exhausted.
 *
 * As bytes are returned from upstream they are written to a local file. Downstream sources read
 * from this file as necessary.
 *

        // After last element, hasNext should be false and calling close() should send Smb2CloseRequest once
        assertFalse(it.hasNext(), "Iterator should be exhausted");

        // Close explicitly to exercise doCloseInternal
        it.close();

        // Verify interactions: one create, two additional directory queries (for fetchMore), one close

  fun sourceEmpty() {
    val mediaType = if (null == null) null else "any/thing; charset=${null}".toMediaType()
    val body = "".decodeHex().toResponseBody(mediaType)
    val source = body.source()
    assertThat(source.exhausted()).isTrue()
    assertThat(source.readUtf8()).isEqualTo("")
  }

  @Test
  fun sourceClosesUnderlyingSource() {
    var closed = false

    val body: ResponseBody =
      object : ResponseBody() {

        }
        is SocketException -> {
          // Conscrypt, JDK 8 (>= 292), JDK 9
        }
        else -> {
          assertThat(expected.message).isEqualTo("exhausted all routes")
        }
      }
    }
  }

  @Test
  fun commonNameIsNotTrusted() {
    serverCert =
      HeldCertificate
        .Builder()
        .signedBy(serverIntermediateCa)

        assertTrue(it.hasNext());
        assertEquals("b", it.next().getName(), "Next element should skip '.' and '..'");
        assertFalse(it.hasNext(), "Iterator exhausted after valid entries");
        verify(tree, times(1)).release(); // closed after exhaustion
    }

    @ParameterizedTest
    @ValueSource(strings = { "", "file.txt", "subdir" })