self = <tests.unit.Arithmetic.Addition testMethod=OnePlusTwo>
@testcase("One plus two is four.")
def OnePlusTwo(self) -> None:
"""One plus two is four - a deliberately failing testcase."""
print("adding 1 and 2", file=sys.stderr)
> self.assertEqual(4, 1 + 2)
E AssertionError: 4 != 3
tests/unit/Arithmetic.py:30: AssertionError