@Path("{tunnel}")
    public TunnelResource getTunnel(@PathParam("tunnel") String tunnelUUID)
            throws GuacamoleException {

        Map<String, UserTunnel> tunnels = session.getTunnels();

        // Pull tunnel with given UUID
        final UserTunnel tunnel = tunnels.get(tunnelUUID);
        if (tunnel == null)
            throw new GuacamoleResourceNotFoundException("No such tunnel.");

        // Return corresponding tunnel resource
        return tunnelResourceFactory.create(session.getAuthenticatedUser(), tunnel);

    }
Retrieves the tunnel having the given UUID, returning a TunnelResource
representing that tunnel. If no such tunnel exists, an exception will be
thrown.

@param tunnelUUID
    The UUID of the tunnel to return via a TunnelResource.

@return
    A TunnelResource which represents the tunnel having the given UUID.

@throws GuacamoleException
    If no such tunnel exists.
guacamole/src/main/java/org/apache/guacamole/rest/tunnel/TunnelCollectionResource.java