assert backend.get_callback_number() == ""
with test_utils.expected(Exception):
recent = list(backend.get_recent())
with test_utils.expected(Exception):
messages = list(backend.get_messages())
finally:
assert backend.get_callback_number() == ""
with test_utils.expected(Exception):
recent = list(backend.get_recent())
with test_utils.expected(Exception):
messages = list(backend.get_messages())
finally: