code: public static void removeUserSession(final String _sessionId)
      {
          if (RegistryManager.getCache().containsKey(_sessionId)) {
              RegistryManager.registerLogout4History(
                              RegistryManager.getCache().get(_sessionId).getUserName(), _sessionId);
              RegistryManager.getCache().remove(_sessionId);
          }
  
      }
docs: Removes the user session.
  
  @param _sessionId the session id