docs: public void disconnect() throws IOException {
          if (currentSession != null && currentSession.isOpen()) {
              synchronized (currentSession) {
                  this.currentSession.close(new CloseReason(
                          CloseReason.CloseCodes.NORMAL_CLOSURE,
                          RTMClient.class.getCanonicalName() + " did it"
                  ));
              }
          }
      }