code: public ANRWatchDog setANRListener(ANRListener listener) {
          if (listener == null) {
              _anrListener = DEFAULT_ANR_LISTENER;
          } else {
              _anrListener = listener;
          }
          return this;
      }
docs: Sets an interface for when an ANR is detected.
  If not set, the default behavior is to throw an error and crash the application.
  
  @param listener The new listener or null
  @return itself for chaining.