When calling this:
stats/jobs/accounts/a33r5?start_time=2017-01-01&end_time=2017-01-05&granularity=TOTAL&placement=ALL_ON_TWITTER&metric_groups=ENGAGEMENT&entity=CAMPAIGN&entity_ids=11560570
A success message is returned and a URL is given.
After uncompressing the gz file, the JSON contains an empty data array, even though the UI shows data.