1. from common import BaseError
    2. class TestError(BaseError):
    3. pass
    4. def test_error():
    5. raise TestError("test error.")
    6. # Traceback (most recent call last):
    7. # File "<stdin>", line 55, in <module>
    8. # File "<stdin>", line 6, in test_error
    9. # TestError: test error.