private void fireTunnelClosedEvent(AuthenticatedUser authenticatedUser,
            Credentials credentials, GuacamoleTunnel tunnel)
            throws GuacamoleException {
        listenerService.handleEvent(new TunnelCloseEvent(authenticatedUser,
                credentials, tunnel));
    }
Notifies bound listeners that a tunnel is to be closed.
Listeners are allowed to veto a request to close a tunnel by throwing any
GuacamoleException.

@param authenticatedUser
     The AuthenticatedUser associated with the user for whom the tunnel
     is being closed.

@param credentials
     Credentials that authenticate the user.

@param tunnel
     The tunnel that was connected.

@throws GuacamoleException
    If thrown by a listener.
guacamole/src/main/java/org/apache/guacamole/tunnel/TunnelRequestService.java