def METHOD_NAME(self):
    """
    Test an empty node comment (only a space) under json.
    """
    self.server.manager(MGR_CMD_SET, NODE,
                        {'comment': ' '}, id=self.mom.shortname)
    cmd = os.path.join(self.server.pbs_conf['PBS_EXEC'],
                       'bin', 'pbsnodes') + ' -av -Fjson'
    ret = self.du.run_cmd(self.server.hostname, cmd=cmd)
    n_out = "\n".join(ret['out'])
    try:
        json.loads(n_out)
    except ValueError:
        self.logger.info(n_out)
        self.assertFalse(True, "Json failed to load")