code: func validateRef(ctx *validation.Context, configSet, path string, content []byte) error {
  	ctx.SetFile(path)
  	// cq.cfg has been disallowed since Feb 1, 2019.
  	// keep this error in place till Apr 1, 2019, to encourage clients remove this
  	// config file from their repo.
  	ctx.Errorf("cq.cfg is no longer used and has no effect. Please, delete cq.cfg in your repo.")
  	ctx.Errorf("cq.cfg is replaced by commit-queue.cfg")
  	return nil
  }
docs: // validateRefCfg validates legacy ref-specific cq.cfg.
  // Validation result is returned via validation ctx,
  // while error returned directly implies only a bug in this code.