code: def get_handler():
      
      host, port, signum = _pdbhandler._registered()
      if signum:
          return Handler(host if host else DFLT_ADDRESS[0].encode(),
                         port if port else DFLT_ADDRESS[1], signum)
docs: Return the handler as a named tuple.
  
      The named tuple attributes are 'host', 'port', 'signum'.
      Return None when no handler has been registered.