def METHOD_NAME(db_session, new_proposal) -> None:
    assert new_proposal.title == "Test Proposal"
    new_proposal.video_url = 'https://www.youtube.com/watch?v=dQw4w9WgXcQ'
    db_session.commit()
    assert new_proposal.video_source == 'youtube'
    assert new_proposal.video_id == 'dQw4w9WgXcQ'
    new_proposal.video_url = None
    db_session.commit()
    assert new_proposal.video_source is None
    assert new_proposal.video_id is None