    def test_uses_default(self):
        account_info = self._make_sqlite_account_info(
            env={
                'HOME': self.home,
                'USERPROFILE': self.home,
            }
        )
        actual_path = os.path.abspath(account_info.filename)
        assert os.path.join(self.home, '.b2_account_info') == actual_path
The software checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the software to perform invalid actions when the resource is in an unexpected state.