def test_changing_var_in_outer_env(self):
env = Environment(outer=Environment({"my-var": 1}))
env.defining_env("my-var")["my-var"] = 2
assert_equals(2, env["my-var"])
def test_finding_defining_env(self):
outer = Environment({"my-var": 1})
inner = Environment(outer=outer)
assert_equals(outer, inner.defining_env("my-var"))