docs: def absent(name, user=None, config=None):
      '''
      Verifies that the specified host is not known by the given user
  
      name
          The host name
          Note that only single host names are supported.  If foo.example.com
          and bar.example.com are the same machine and you need to exclude both,
          you will need one Salt state for each.
  
      user
          The user who owns the ssh authorized keys file to modify
  
      config
          The location of the authorized keys file relative to the user's home
          directory, defaults to ".ssh/known_hosts". If no user is specified,
          defaults to "/etc/ssh/ssh_known_hosts". If present, must be an
          absolute path when a user is not specified.
      '''
      ret = {'name': name,
             'changes': {},
             'result': True,
             'comment': ''}
  
      if not user:
          config = config or '/etc/ssh/ssh_known_hosts'
      else:
          config = config or '.ssh/known_hosts'
  
      if not user and not os.path.isabs(config):
          comment = 'If not specifying a "user", specify an absolute "config".'
          ret['result'] = False
          return dict(ret, comment=comment)
  
      known_host = __salt__['ssh.get_known_host_entries'](user=user, hostname=name, config=config)
      if not known_host:
          return dict(ret, comment='Host is already absent')
  
      if __opts__['test']:
          comment = 'Key for {0} is set to be removed from {1}'.format(name,
                                                                       config)
          ret['result'] = None
          return dict(ret, comment=comment)
  
      rm_result = __salt__['ssh.rm_known_host'](user=user, hostname=name, config=config)
      if rm_result['status'] == 'error':
          return dict(ret, result=False, comment=rm_result['error'])
      else:
          return dict(ret,
                      changes={'old': known_host, 'new': None},
                      result=True,
                      comment=rm_result['comment'])