The argument is deprecated and has no effect. Fixes warning:
tests/test_random.py::test_contains
.../hypothesis/internal/validation.py:157: HypothesisDeprecationWarning: You should remove the average_size argument, because it is deprecated and no longer has any effect. Please open an issue if the default distribution of examples does not work for you.
since="2018-03-10",
The argument is deprecated and has no effect. Fixes warning: