def _generate_tables(self, files):
        if self.config.features is not None and self.config.columns is not None:
            if sorted(field.name for field in self.info.features.arrow_schema) != sorted(self.config.columns):
                raise ValueError(
                    f"Tried to load parquet data with columns '{self.config.columns}' with mismatching features '{self.info.features}'"
                )
        filter_expr = (
            pq.filters_to_expression(self.config.filters)
            if isinstance(self.config.filters, list)
            else self.config.filters
        )
        for file_idx, file in enumerate(itertools.chain.from_iterable(files)):
            with open(file, "rb") as f:
                parquet_fragment = ds.ParquetFileFormat().make_fragment(f)
                if parquet_fragment.row_groups:
                    batch_size = self.config.batch_size or parquet_fragment.row_groups[0].num_rows
                    try: