private var coordinatorWakeUpAt = 0L

  /**
   * When we need a new thread to run tasks, we call [Backend.execute]. A few microseconds later we
   * expect a newly-started thread to call [Runnable.run]. We shouldn't request new threads until
   * the already-requested ones are in service, otherwise we might create more threads than we need.
   *
   * We use [executeCallCount] and [runCallCount] to defend against starting more threads than we

    // If we do have a route selector, use its routes.
    return localRouteSelector.hasNext()
  }

  /**
   * Return the route from [connection] if it should be retried, even if the connection itself is
   * unhealthy. The biggest gotcha here is that we shouldn't reuse routes from coalesced
   * connections.
   */
  private fun retryRoute(connection: RealConnection): Route? {
    return connection.withLock {
      when {

  }

  /**
   * Sends any initial frames and starts reading frames from the remote peer. This should be called
   * after [Builder.build] for all new connections.
   *
   * @param sendConnectionPreface true to send connection preface frames. This should always be true
   *     except for in tests that don't check for a connection preface.
   * @param taskRunner the TaskRunner to use, daemon by default.

    connection.calls.add(CallReference(this, callStackTrace))
  }

  /**
   * Releases resources held with the request or response of [exchange]. This should be called when
   * the request completes normally or when it fails due to an exception, in which case [e] should
   * be non-null.
   *
   * If the exchange was canceled or timed out, this will wrap [e] in an exception that provides

  /**
   * If true, no new exchanges can be created on this connection. It is necessary to set this to
   * true when removing a connection from the pool; otherwise a racing caller might get it from the
   * pool when it shouldn't. Symmetrically, this must always be checked before returning a
   * connection from the pool.
   *
   * Once true this is always true. Guarded by this.
   */
  var noNewExchanges = false

  /**

    Uvicorn and others support a `--reload` option that is useful during development.

    The `--reload` option consumes much more resources, is more unstable, etc.

    It helps a lot during **development**, but you **shouldn't** use it in **production**.

## Hypercorn with Trio

  internal var errorException: IOException? = null

  init {
    if (headers != null) {
      check(!isLocallyInitiated) { "locally-initiated streams shouldn't have headers yet" }
      headersQueue += headers
    } else {
      check(isLocallyInitiated) { "remotely-initiated streams should have headers" }
    }
  }

  /**
   * Returns true if this stream is open. A stream is open until either:
   *

    assertThat(synStream.streamId).isEqualTo(3)
    assertThat(synStream.associatedStreamId).isEqualTo(-1)
    assertThat(synStream.headerBlock).isEqualTo(headerEntries("a", "artichaut"))
  }

  /** A server RST_STREAM shouldn't prevent the client from consuming the response body.  */
  @Test fun serverResponseBodyRstStream() {
    // Write the mocking script.
    peer.sendFrame().settings(Settings())
    peer.acceptFrame() // ACK

## Version 4.5.0

_2020-04-06_

**This release fixes a severe bug where OkHttp incorrectly detected and recovered from unhealthy
connections.** Stale or canceled connections were incorrectly attempted when they shouldn't have
been, leading to rare cases of infinite retries. Please upgrade to this release!

 *  Fix: don't return stale DNS entries in `DnsOverHttps`. We were caching DNS results indefinitely

## Return the token

The response of the `token` endpoint must be a JSON object.

It should have a `token_type`. In our case, as we are using "Bearer" tokens, the token type should be "`bearer`".

And it should have an `access_token`, with a string containing our access token.