* become idle after the [onResponse][Callback.onResponse] or [onFailure][Callback.onFailure]
   * callback has returned. Synchronous calls become idle once [execute()][Call.execute] returns.
   * This means that if you are doing synchronous calls the network layer will not truly be idle
   * until every returned [Response] has been closed.
   */
  var idleCallback: Runnable? = null

   *
   * [grpc]: https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md
   */
  open fun isDuplex(): Boolean = commonIsDuplex()

  /**
   * Returns true if this body expects at most one call to [writeTo] and can be transmitted
   * at most once. This is typically used when writing the request body is destructive and it is not
   * possible to recreate the request body after it has been sent.
   *

        return headersQueue.removeFirst()
      }
      throw errorException ?: StreamResetException(errorCode!!)
    }
  }

  /**
   * Returns the trailers. It is only safe to call this once the source stream has been completely
   * exhausted.
   */
  @Throws(IOException::class)
  fun trailers(): Headers {
    this.withLock {

    builder.interceptors.toImmutableList()

  /**
   * Returns an immutable list of interceptors that observe a single network request and response.
   * These interceptors must call [Interceptor.Chain.proceed] exactly once: it is an error for
   * a network interceptor to short-circuit or repeat a network request.
   */
  @get:JvmName("networkInterceptors")
  val networkInterceptors: List<Interceptor> =

 *  Fix: Don't leak a connection when a call is canceled immediately preceding the `onFailure()`
    callback.

 *  Fix: Apply call timeouts when connecting duplex calls, web sockets, and server-sent events.
    Once the streams are established no further timeout is enforced.

 *  Fix: Retain the `Route` when a connection is reused on a redirect or other follow-up. This was

    cache.close()
    createNewCache()

    // The journal will have no record that 'a' was removed. It will have an entry for 'a', but when
    // it tries to read the cache files, it will find they were deleted. Once it encounters an entry
    // with missing cache files, it should remove it from the cache entirely.
    assertThat(cache.size()).isEqualTo(4)
    assertThat(cache["a"]).isNull()
    assertThat(cache.size()).isEqualTo(2)

    checkEntry(entry1, "custom-bar", "custom-header", 55)
    val entry2 = hpackReader!!.dynamicTable[readerHeaderTableLength() - 2]!!
    checkEntry(entry2, "custom-baz", "custom-header", 55)

    // Once a header field is decoded and added to the reconstructed header
    // list, it cannot be removed from it. Hence, foo is here.
    assertThat(hpackReader!!.getAndResetHeaderList()).isEqualTo(headerBlock)

 *  New: Kotlin-specific APIs for request tags. Kotlin language users can lookup tags with a type
    parameter only, like `request.tag<MyTagClass>()`.
 *  New: MockWebServer has improved support for HTTP/1xx responses. Once you've migrated to the new
    `mockwebserver3` package, there's a new field, `MockResponse.informationalResponses`.
 *  Fix: Don't interpret trailers as headers after an HTTP/100 response. This was a bug only when

        set(Settings.INITIAL_WINDOW_SIZE, OKHTTP_CLIENT_WINDOW_SIZE)
      }
    }

  /**
   * Settings we receive from the peer. Changes to the field are guarded by this. The instance is
   * never mutated once it has been assigned.
   */
  var peerSettings = DEFAULT_SETTINGS

  /** The bytes consumed and acknowledged by the application. */
  val readBytes: WindowCounter = WindowCounter(streamId = 0)

 * space-sensitive applications should set a conservative limit.
 *
 * Clients call [edit] to create or update the values of an entry. An entry may have only one editor
 * at one time; if a value is not available to be edited then [edit] will return null.
 *
 *  * When an entry is being **created** it is necessary to supply a full set of values; the empty