public GuacamoleHTTPTunnel get(String tunnelSessionToken) {

        // Update the last access time
        GuacamoleHTTPTunnel tunnel = tunnelMap.get(tunnelSessionToken);
        if (tunnel != null)
            tunnel.access();

        // Return tunnel, if any
        return tunnel;

    }
Returns the GuacamoleTunnel associated with the given tunnel-specific
session token, wrapped within a GuacamoleHTTPTunnel. If the no tunnel
is associated with the given token, null is returned.

@param tunnelSessionToken
    The tunnel-specific session token of the HTTP tunnel to retrieve.

@return
    The GuacamoleTunnel associated with the given tunnel-specific
    session token, wrapped within a GuacamoleHTTPTunnel, if such a
    tunnel exists, or null if there is no such tunnel.
guacamole-common/src/main/java/org/apache/guacamole/servlet/GuacamoleHTTPTunnelMap.java