test_foo.py

from unittest import TestCase

from hypothesis import given
from hypothesis import strategies


class TestFoo(TestCase):

    def setUp(self):
        self.foo = 'meow'

    @given(strategies.none())
    def test_with_hypo(self, nada):
        assert self.foo == 'meow'
        self.foo = 'kitten'

    def test_no_hypo(self):
        assert self.foo == 'meow'
        self.foo = 'kitten'