How to use group_by parameter in snapshot.compare_to()? (Python 3.4 tracemalloc module) -

How to use group_by parameter in snapshot.compare_to()? (Python 3.4 tracemalloc module) -

according python 3.4 docs tracemalloc module, function comapre_to() takes mandatory str sec argument. info on how utilize this, docs direct statistics module. can't find relevant documentation on how utilize parameter.

how 1 utilize group_by param?

python python-3.x documentation