Test failure - test_collection.TestCollection.test_index_filter

 [2020/04/27 21:09:53.860] ======================================================================

 [2020/04/27 21:09:53.860] FAIL [0.033s]: test_index_filter (test_collection.TestCollection)

 [2020/04/27 21:09:53.860] ----------------------------------------------------------------------

 [2020/04/27 21:09:53.860] Traceback (most recent call last):

 [2020/04/27 21:09:53.860]   File "/data/mci/e02cdbd4d09c5ecb23ef3468a44c35dc/src/test/__init__.py", line 447, in wrap

 [2020/04/27 21:09:53.860]     return f(*args, **kwargs)

 [2020/04/27 21:09:53.860]   File "/data/mci/e02cdbd4d09c5ecb23ef3468a44c35dc/src/test/test_collection.py", line 626, in test_index_filter

 [2020/04/27 21:09:53.860]     {"x": {"$exists": True}}]})

 [2020/04/27 21:09:53.860] AssertionError: OperationFailure not raised