public GuacamoleHTTPTunnel remove(String tunnelSessionToken) {
        return tunnelMap.remove(tunnelSessionToken);
    }
Removes the GuacamoleTunnel associated with the given tunnel-specific
session token, if such a tunnel exists. The original tunnel is returned
wrapped within a GuacamoleHTTPTunnel.

@param tunnelSessionToken
    The tunnel-specific session token of the HTTP tunnel to remove
    (deregister).

@return
    The GuacamoleTunnel having the given tunnel-specific session token,
    if such a tunnel exists, wrapped within a GuacamoleHTTPTunnel, or
    null if no such tunnel exists and no removal was performed.
guacamole-common/src/main/java/org/apache/guacamole/servlet/GuacamoleHTTPTunnelMap.java