The consequence of this golden test helper function for testing the distinct command is that the expected results are repeated in the golden files. An example of the duplication in practice can be seen here:

https://github.com/10gen/mongo/blob/2a5142aadfffe6e09f3caac306095b9c1c523673/jstests/query_golden/expected_output/distinct_scan.md#L3-L6