docs: def pbm(self):
          """ Plumbum lazy property """
          if not self.disable_rpyc:
              from plumbum import SshMachine
              return SshMachine(host=self.private_hostname, user=self.username,
                                keyfile=self.key_filename,
                                ssh_opts=["-o", "UserKnownHostsFile=/dev/null",
                                          "-o", "StrictHostKeyChecking=no"])
          else:
              return None