docs: Index createIndexForColumns(int[] columns) {
  
          HsqlName indexName = database.nameManager.newAutoName("IDX_T",
              getSchemaName(), getName(), SchemaObject.INDEX);
  
          try {
              Index index = createAndAddIndexStructure(indexName, columns, null,
                  null, false, false, false, false);
  
              return index;
          } catch (Throwable t) {
              return null;
          }
      }