code: synchronized void unregisterRequest(HttpRequest request) {
  		assertTrue(this == request.requestManager);
  		boolean removed = activeRequests.remove(request);
  		assertTrue(removed, "Attempted to unregister missing request: %s", request);
  
  		if (removed) {
  			notifyRequestFinished(request);
  		}
  	}
docs: Unregisters active request