code: func checkAndInitTablePriv(ctx sessionctx.Context, dbName, tblName string, is infoschema.InfoSchema, user string, host string) error {
  	ok, err := tableUserExists(ctx, user, host, dbName, tblName)
  	if err != nil {
  		return err
  	}
  	if ok {
  		return nil
  	}
  	// Entry does not exist for user-host-db-tbl. Insert a new entry.
  	return initTablePrivEntry(ctx, user, host, dbName, tblName)
  }
docs: // checkAndInitTablePriv checks if table scope privilege entry exists in mysql.Tables_priv.
  // If unexists, insert a new one.