code: @NonNull
      public final synchronized ChronosListener createListener() {
          final int connectorId = mNextConnectorId.getAndIncrement();
          final ChronosListener result = new ChronosListener(connectorId);
  
          mListeners.put(connectorId, result);
  
          return result;
      }
docs: Creates a new ServiceConnector instance. Do not call this method twice for a same object,
  instead use {@link #getListener(int)} method.
  
  @return a created ServiceConnector