docs: def _validate_ssh_minion_opts(opts):
      '''
      Ensure we're not using any invalid ssh_minion_opts. We want to make sure
      that the ssh_minion_opts does not override any pillar or fileserver options
      inherited from the master config. To add other items, modify the if
      statement in the for loop below.
      '''
      ssh_minion_opts = opts.get('ssh_minion_opts', {})
      if not isinstance(ssh_minion_opts, dict):
          log.error('Invalidly-formatted ssh_minion_opts')
          opts.pop('ssh_minion_opts')
  
      for opt_name in list(ssh_minion_opts):
          if re.match('^[a-z0-9]+fs_', opt_name, flags=re.IGNORECASE) \
                  or ('pillar' in opt_name and not 'ssh_merge_pillar' == opt_name) \
                  or opt_name in ('fileserver_backend',):
              log.warning(
                  '\'%s\' is not a valid ssh_minion_opts parameter, ignoring',
                  opt_name
              )
              ssh_minion_opts.pop(opt_name)