(base) ➜  test_case cat bad1.yml
# python test.py bad1.yml --test.a 2 would give error
test:
  type: TestModule
  b: test
(base) ➜  test_case cat bad2.yml
# python main.py bad2.yml --test.b test would give error
test:
  a: 1
  b: null
(base) ➜  test_case cat main.py
from typing import Optional
from utilsd.config import PythonConfig, configclass, Registry, RegistryConfig


class TEST(metaclass=Registry, name="test"):
    pass


@TEST.register_module()
class TestModule:
    def __init__(self, a: int = 1, b: Optional[str] = None):
        self.a = a
        self.b = b


@configclass
class TestConfig(PythonConfig):
    test: RegistryConfig[TEST]


if __name__ == "__main__":
    config = TestConfig.fromcli()
    print(config)
(base) ➜  test_case cat README.md
`python main.py bad1.yml --test.a 2` would give error because test.a is not in bad1.yml even if a has a default value.
`python main.py bad2.yml --test.b test` would give error because test.b is set to null in bad2.yml.