/** Dispatcher is not [Lockable] because we don't want that type in our public API. */
internal fun Dispatcher.assertLockNotHeld() {
  if (assertionsEnabled && Thread.holdsLock(this)) {
    throw AssertionError("Thread ${Thread.currentThread().name} MUST NOT hold lock on $this")
  }
}

/**
 * Returns the string "OkHttp" unless the library has been shaded for inclusion in another library,