private var http2Connection: Http2Connection? = null

  internal val lock: ReentrantLock = ReentrantLock()

  // These properties are guarded by [lock].

  /**
   * 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

   * the event source has already been closed or canceled.
   */
  fun cancel()

  fun interface Factory {
    /**
     * Creates a new event source and immediately returns it. Creating an event source initiates an
     * asynchronous process to connect the socket. Once that succeeds or fails, `listener` will be

    initialization order of companion objects.


## Version 4.7.1

_2020-05-18_

 *  Fix: Pass the right arguments in the trust manager created for `addInsecureHost()`. Without the
    fix insecure hosts crash with an `IllegalArgumentException` on Android.


## Version 4.7.0

_2020-05-17_

    private const val FILE_HEADER_SIZE = 32L

    /**
     * Creates a new relay that reads a live stream from [upstream], using [file] to share that data
     * with other sources.
     *
     * **Warning:** callers to this method must immediately call [newSource] to create a source and
     * close that when they're done. Otherwise a handle to [file] will be leaked.
     */

    logger.log(logLevel, message, t)
  }

  open fun isCleartextTrafficPermitted(hostname: String): Boolean = true

  /**
   * Returns an object that holds a stack trace created at the moment this method is executed. This
   * should be used specifically for [java.io.Closeable] objects and in conjunction with
   * [logCloseableLeak].
   */
  open fun getStackTraceForCloseable(closer: String): Any? {

/**
 * An OkHttp interceptor which logs request and response information. Can be applied as an
 * [application interceptor][OkHttpClient.interceptors] or as a [OkHttpClient.networkInterceptors].
 *
 * The format of the logs created by this class should not be considered stable and may
 * change slightly between releases. If you need a stable logging format, use your own interceptor.
 */
class HttpLoggingInterceptor
  @JvmOverloads
  constructor(

 *
 * To make HTTPS calls using an HTTP proxy server OkHttp must first negotiate a connection with
 * the proxy. This proxy connection is called a "TLS Tunnel" and is specified by
 * [RFC 2817][1]. The HTTP CONNECT request that creates this tunnel connection is special: it
 * does not participate in any [interceptors][Interceptor] or [event listeners][EventListener]. It
 * doesn't include the motivating request's HTTP headers or even its full URL; only the target

This [sample factory](https://github.com/square/okhttp/blob/master/samples/guide/src/main/java/okhttp3/recipes/PrintEvents.java) creates a unique ID for each call and uses that ID to differentiate calls in log messages.

```java

    assertContent("This comes after a busted connection", response2)

    // Check that a fresh connection was created, either immediately or after attempting reuse.
    // We know that a fresh connection was created if the server recorded a request with sequence
    // number 0. Since the client may have attempted to reuse the broken connection just before

            addLenient(line.substring(0, index), line.substring(index + 1))
          }
          line[0] == ':' -> {
            // Work around empty header names and header names that start with a colon (created by old
            // broken SPDY versions of the response cache).
            addLenient("", line.substring(1)) // Empty header name.
          }
          else -> {
            // No header name.