code: public GuacamoleHTTPTunnel get(String uuid) {
  
          // Update the last access time
          GuacamoleHTTPTunnel tunnel = tunnelMap.get(uuid);
          if (tunnel != null)
              tunnel.access();
  
          // Return tunnel, if any
          return tunnel;
  
      }
docs: Returns the GuacamoleTunnel having the given UUID, wrapped within a
  GuacamoleHTTPTunnel. If the no tunnel having the given UUID is
  available, null is returned.
  
  @param uuid
  The UUID of the tunnel to retrieve.
  
  @return
  The GuacamoleTunnel having the given UUID, wrapped within a
  GuacamoleHTTPTunnel, if such a tunnel exists, or null if there is no
  such tunnel.