docs: def cli(self):
          """ cli lazy property """
          client = paramiko.SSHClient()
          client.set_missing_host_key_policy(paramiko.AutoAddPolicy())
  
          client.connect(hostname=self.private_hostname,
                         username=self.username,
                         key_filename=self.key_filename,
                         timeout=self.timeout,
                         look_for_keys=self.look_for_keys)
          # set keepalive
          transport = client.get_transport()
          transport.set_keepalive(3)
          return client