In https://github.com/apache/incubator-livy/blob/master/docs/rest-api.md#response-body - shouldn't 'size' be replaced with 'total'? Put it this way, if I use 'total' a Java client works, whereas it doesn't if I use 'size'.
This change would also make the response body consistence with that for GET /batches: https://github.com/apache/incubator-livy/blob/master/docs/rest-api.md#response-body-9 (although perhaps that should use 'batches' rather than 'sessions'?!).
