in upload.py [0:0]
def __enter__(self) -> SessionConfigurator:
"""Initiate a Bigquery session and return the session_id."""
job = self._bigquery_client.query(
"SELECT 1;", # a query that won't fail
job_config=bigquery.QueryJobConfig(create_session=True),
)
assert job.session_info.session_id is not None
self._session_cfg = SessionConfigurator(job.session_info.session_id)
job.result() # wait job completion
return self._session_cfg