message: Fixed undefined "pooled str" column
diff: @@ -35,7 +35,7 @@ export interface Column<T> {
  }
  export function UndefinedColumn<T extends ColumnType>(rowCount: number, type: T): Column<T['@type']> {
  - const value: Column<T['@type']>['value'] = type.kind === 'str' ? row => '' : row => 0;
  + const value: Column<T['@type']>['value'] = type.isString ? row => '' : row => 0;
  return {
  '@type': type,
  isDefined: false,
  