code: private void fireConnectionClosedOnError(
              final Throwable cause) {
          assertUnlocked();
  
          BOSHClientConnEvent event = null;
          for (BOSHClientConnListener listener : connListeners) {
              if (event == null) {
                  event = BOSHClientConnEvent
                          .createConnectionClosedOnErrorEvent(
                          this, pendingRequestAcks, cause);
              }
              try {
                  listener.connectionEvent(event);
              } catch (Exception ex) {
                  LOG.log(Level.WARNING, UNHANDLED, ex);
              }
          }
      }
docs: Notifies all connection listeners that the session has been
  terminated due to the exceptional condition provided.
  
  @param cause cause of the termination