def survey_session(df):
    """Identify the session containing the survey request."""
    sessions = df["sessions"]
    survey_request = df["survey_request"]
    survey_request_id = survey_request['id']
    for s in sessions:
        if survey_request_id in [r['id'] for r in s]:
            return [r for r in s if 'is_pageview' in r and r['is_pageview'] == 'true']