In implementing pandas-gbq integration with the new, fasterquery_and_wait method, a test failure raised the issue that some request body details in a custom job configuration are being dropped. See:https://github.com/googleapis/python-bigquery-pandas/pull/722/files/7739f41989c5d0effbaf66070c6b94b6c3840506#r1459296431

Steps to reproduce

1. Create aQueryJobConfig with unknown or invalid parameters viafrom_api_repr()
2. Pass thejob_config toquery_and_wait().
3. Observe that the extra parameters are not sent.

Code example

importgoogle.cloud.bigqueryclient=google.cloud.bigquery.Client()project_id="swast-scratch"job_config=google.cloud.bigquery.QueryJobConfig.from_api_repr(        {"copy": {"sourceTable": {"projectId":project_id,"datasetId":"publicdata:samples","tableId":"wikipedia",                },"destinationTable": {"projectId":project_id,"datasetId":"publicdata:samples","tableId":"wikipedia_copied",                },            }        })client.query_and_wait("select 1",job_config=job_config)

Stack trace

No stack trace is produced, even though one should be due to an invalid configuration.