protected abstract GuacamoleTunnel doConnect(HttpServletRequest request) throws GuacamoleException ;

protected abstract GuacamoleTunnel doConnect ( HttpServletRequest request ) throws GuacamoleException ;
called whenever the javascript guacamole client makes a connection request via http . it it up to the implementor of this function to define what conditions must be met for a tunnel to be configured and returned as a result of this connection request ( whether some sort of credentials must be specified , for example ) .
