Final Class Yiisoft\Yii\DataView\GridView\Column\SerialColumnRenderer

                public function renderBody(ColumnInterface $column, Cell $cell, DataContext $context): Cell
{
    $index = $context->preparedDataReader instanceof OffsetPaginator
        ? $context->preparedDataReader->getOffset() + $context->index + 1
        : $context->index + 1;
    return $cell
        ->addAttributes($column->bodyAttributes)
        ->content((string) $index);
}

            

                public function renderColumn(ColumnInterface $column, Cell $cell, GlobalContext $context): Cell
{
    return $cell->addAttributes($column->columnAttributes);
}

            

                public function renderFooter(ColumnInterface $column, Cell $cell, GlobalContext $context): Cell
{
    return $cell->content($column->footer ?? '');
}

            

                public function renderHeader(ColumnInterface $column, Cell $cell, GlobalContext $context): Cell
{
    return $cell->content($column->header ?? '#');
}