headersQueue += headers
    } else {
      check(isLocallyInitiated) { "remotely-initiated streams should have headers" }
    }
  }

  /**
   * Returns true if this stream is open. A stream is open until either:
   *
   *  * A `SYN_RESET` frame abnormally terminates the stream.
   *  * Both input and output streams have transmitted all data and headers.
   *

        addressState.concurrentCallCapacity += connection.allocationLimit
      }
    }

    // Find the longest-idle connections in 2 categories:
    //
    //  1. OLD: Connections that have been idle for at least keepAliveDurationNs. We close these if
    //     we find them, regardless of what the address policies need.
    //

  private val typeHintStack = mutableListOf<Any?>()

  /**
   * The type hint for the current object. Used to pick adapters based on other fields, such as
   * in extensions which have different types depending on their extension ID.
   */
  var typeHint: Any?
    get() = typeHintStack.lastOrNull()
    set(value) {
      typeHintStack[typeHintStack.size - 1] = value
    }

 * 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

          maskCursor.seek(messageFrameBuffer.size - frameLength)
          toggleMask(maskCursor, maskKey!!)
          maskCursor.close()
        }
      }

      if (isFinalFrame) break // We are exhausted and have no continuations.

      readUntilNonControlFrame()
      if (opcode != OPCODE_CONTINUATION) {
        throw ProtocolException("Expected continuation opcode. Got: ${opcode.toHexString()}")
      }
    }
  }

      } catch (_: InterruptedException) {
        Thread.currentThread().interrupt() // Retain interrupted status.
      }
    }

    check(::publicSuffixListBytes.isInitialized) {
      // May have failed with an IOException
      "Unable to load $PUBLIC_SUFFIX_RESOURCE resource from the classpath."
    }

    // Break apart the domain into UTF-8 labels, i.e. foo.bar.com turns into [foo, bar, com].

    val serverSocket = this.serverSocket ?: return // If this is null, start() must have failed.

    // Cause acceptConnections() to break out.
    serverSocket.close()

    // Await shutdown.
    for (queue in taskRunner.activeQueues()) {
      if (!queue.idleLatch().await(5, TimeUnit.SECONDS)) {
        throw IOException("Gave up waiting for queue to shut down")
      }
    }
    taskRunnerBackend.shutdown()

      if (request.isHttps && cacheResponse.handshake == null) {
        return CacheStrategy(request, null)
      }

      // If this response shouldn't have been stored, it should never be used as a response source.
      // This check should be redundant as long as the persistence store is well-behaved and the
      // rules are constant.

        .isEqualTo("response body")
      requestBody.close()
      assertThat(responseBody.readUtf8Line()).isNull()
    }
    body.awaitSuccess()
  }

  /**
   * Duplex calls that have follow-ups are weird. By the time we know there's a follow-up we've
   * already split off another thread to stream the request body. Because we permit at most one

## Version 4.2.1

_2019-10-02_

 *  Fix: In 4.1.0 we introduced a performance regression that prevented connections from being
    pooled in certain situations. We have good test coverage for connection pooling but we missed
    this because it only occurs if you have proxy configured and you share a connection pool among
    multiple `OkHttpClient` instances.