- CallStart 
 - **CacheMiss**
 - ProxySelectStart
 - ... Standard Events ...
 - CallEnd
        
### Conditional Cache Hit
 
When cache flags require checking the cache results are still valid an early cacheConditionalHit event is
received followed by a cache hit or miss.  Critically in the cache hit scenario the server won’t send the response body.

   *
   * Note that transport-layer success (receiving a HTTP response code, headers and body) does not
   * necessarily indicate application-layer success: `response` may still indicate an unhappy HTTP
   * response code like 404 or 500.
   *
   * @throws IOException if the request could not be executed due to cancellation, a connectivity

        // If you throw an exception here then native image building fails half way through
        // silently without rewriting the binary. So we report noisily, but keep going and prefer
        // running most tests still.
        e.printStackTrace()
      }
    }
  }

  private fun registerTest(
    access: Feature.BeforeAnalysisAccess,
    java: Class<*>,
  ) {
    access.registerAsUsed(java)

          if (!exchange.connection.isMultiplexed) {
            // If the "Expect: 100-continue" expectation wasn't met, prevent the HTTP/1 connection
            // from being reused. Otherwise we're still obligated to transmit the request body to
            // leave the connection in a consistent state.
            exchange.noNewExchangesOnConnection()
          }
        }
      } else {
        exchange.noRequestBody()

    HTTP/2 to 16 MiB of unacknowledged data per connection. With this fix there is a limit of 16 MiB
    of unacknowledged data per stream and no per-connection limit.

 *  Fix: Don't close a `Deflater` while we're still using it to compress a web socket message. We
    had a severe bug where web sockets were closed on the wrong thread, which caused
    `NullPointerException` crashes in `Deflater`.

    }
  }

  /** Start another thread, unless a new thread is already scheduled to start. */
  private fun startAnotherThread() {
    lock.assertHeld()
    if (executeCallCount > runCallCount) return // A thread is still starting.

    executeCallCount++
    backend.execute(this@TaskRunner, runnable)
  }

  fun newQueue(): TaskQueue {
    val name = lock.withLock { nextQueueName++ }
    return TaskQueue(this, "Q$name")

    cache["k1"]!!.use { snapshot1 ->
      cache.remove("k1")

      // On Windows files still exist with open with 2 open sources.
      assertThat(readFileOrNull(getCleanFile("k1", 0))).isEqualTo(afterRemoveFileContents)
      assertThat(readFileOrNull(getDirtyFile("k1", 0))).isNull()

      // On Windows files still exist with open with 1 open source.
      snapshot1.assertValue(0, "a")

        fail("Encoding $component $codePoint using $encoding")
      }
      return
    }

    // If the URI has more escaping than the HttpURL, check that the decoded values still match.
    val uriEscaped = uriEscapedCodePoints.indexOf(codePointString) != -1
    if (uriEscaped) {
      if (uri.toString() == httpUrl.toString()) {
        fail("Encoding $component $codePoint using $encoding")

    `NullPointerException` or `OutOfMemoryError`. We now call `Callback.onFailure()` with an
    `IOException` that reports the call as canceled. The triggering exception is still delivered to
    the thread's `UncaughtExceptionHandler`.
 *  Fix: Don't evict incomplete entries when iterating the cache. We had a bug where iterating
    `Cache.urls()` would prevent in-flight entries from being written.

      promoteAndExecute()
    }

  /**
   * The maximum number of requests for each host to execute concurrently. This limits requests by
   * the URL's host name. Note that concurrent requests to a single IP address may still exceed this
   * limit: multiple hostnames may share an IP address or be routed through the same HTTP proxy.
   *
   * If more than [maxRequestsPerHost] requests are in flight when this is invoked, those requests