code: public void invalidate() {
  
          // Close all associated tunnels, if possible
          for (GuacamoleTunnel tunnel : tunnels.values()) {
              try {
                  tunnel.close();
              }
              catch (GuacamoleException e) {
                  logger.debug("Unable to close tunnel.", e);
              }
          }
  
          // Invalidate all user contextx
          for (UserContext userContext : userContexts)
              userContext.invalidate();
  
          // Invalidate the authenticated user object
          authenticatedUser.invalidate();
  
      }
docs: Closes all associated tunnels and prevents any further use of this
  session.