Return a pandas DataFrame from a QueryJob

        Args:
            bqstorage_client ( \
                google.cloud.bigquery_storage_v1beta1.BigQueryStorageClient \
            ):
                **Alpha Feature** Optional. A BigQuery Storage API client. If
                supplied, use the faster BigQuery Storage API to fetch rows
                from BigQuery. This API is a billable API.

                This method requires the ``fastavro`` and
                ``google-cloud-bigquery-storage`` libraries.

                Reading from a specific partition or snapshot is not
                currently supported by this method.

                **Caution**: There is a known issue reading small anonymous
                query result tables with the BQ Storage API. Write your query
                results to a destination table to work around this issue.
            dtypes ( \
                Map[str, Union[str, pandas.Series.dtype]] \
            ):
                Optional. A dictionary of column names pandas ``dtype``s. The
                provided ``dtype`` is used when constructing the series for
                the column specified. Otherwise, the default pandas behavior
                is used.
            progress_bar_type (Optional[str]):
                If set, use the `tqdm <https://tqdm.github.io/>`_ library to
                display a progress bar while the data downloads. Install the
                ``tqdm`` package to use this feature.

                See
                :func:`~google.cloud.bigquery.table.RowIterator.to_dataframe`
                for details.

                ..versionadded:: 1.11.0

        Returns:
            A :class:`~pandas.DataFrame` populated with row data and column
            headers from the query results. The column headers are derived
            from the destination table's schema.

        Raises:
            ValueError: If the `pandas` library cannot be imported.

def to_dataframe(self, bqstorage_client=None, dtypes=None, progress_bar_type=None):
        """Return a pandas DataFrame from a QueryJob

        Args:
            bqstorage_client ( \
                google.cloud.bigquery_storage_v1beta1.BigQueryStorageClient \
            ):
                **Alpha Feature** Optional. A BigQuery Storage API client. If
                supplied, use the faster BigQuery Storage API to fetch rows
                from BigQuery. This API is a billable API.

                This method requires the ``fastavro`` and
                ``google-cloud-bigquery-storage`` libraries.

                Reading from a specific partition or snapshot is not
                currently supported by this method.

                **Caution**: There is a known issue reading small anonymous
                query result tables with the BQ Storage API. Write your query
                results to a destination table to work around this issue.
            dtypes ( \
                Map[str, Union[str, pandas.Series.dtype]] \
            ):
                Optional. A dictionary of column names pandas ``dtype``s. The
                provided ``dtype`` is used when constructing the series for
                the column specified. Otherwise, the default pandas behavior
                is used.
            progress_bar_type (Optional[str]):
                If set, use the `tqdm <https://tqdm.github.io/>`_ library to
                display a progress bar while the data downloads. Install the
                ``tqdm`` package to use this feature.

                See
                :func:`~google.cloud.bigquery.table.RowIterator.to_dataframe`
                for details.

                ..versionadded:: 1.11.0

        Returns:
            A :class:`~pandas.DataFrame` populated with row data and column
            headers from the query results. The column headers are derived
            from the destination table's schema.

        Raises:
            ValueError: If the `pandas` library cannot be imported.
        """
        return self.result().to_dataframe(
            bqstorage_client=bqstorage_client,
            dtypes=dtypes,
            progress_bar_type=progress_bar_type,
        )