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

in a future release! If you’re skipping releases, it’ll be much easier if you upgrade to OkHttp 4.0
as an intermediate step.

#### Vars and Vals

Java doesn’t have language support for properties so developers make do with getters and setters.
Kotlin does have properties and we take advantage of them in OkHttp.

 * **Address**: certificatePinner, connectionSpecs, dns, hostnameVerifier, protocols, proxy,