code: def handle(self, msg):
          
          debug_msg = ': {!r}'.format(msg) if self.debug else ''
          log.debug('request: %d bytes%s', len(msg), debug_msg)
          buf = io.BytesIO(msg)
          code, = util.recv(buf, '>B')
          if code not in self.methods:
              log.warning('Unsupported command: %s (%d)', msg_name(code), code)
              return failure()
  
          method = self.methods[code]
          log.debug('calling %s()', method.__name__)
          reply = method(buf=buf)
          debug_reply = ': {!r}'.format(reply) if self.debug else ''
          log.debug('reply: %d bytes%s', len(reply), debug_reply)
          return reply
docs: Handle SSH message from the SSH client and return the response.