import abc


class Mode(metaclass=abc.ABCMeta):
    @property
    @abc.abstractmethod
    def name(self) -> str:
        """
        A string naming this mode (e.g. "ECB", "CBC").
        """

    @abc.abstractmethod
    def validate_for_algorithm(self, algorithm: str) -> None:
        """
        Checks that all the necessary invariants of this (mode, algorithm)
        combination are met.
        """


def _check_aes_key_length(self: Mode, algorithm: str) -> None:
    pass


class ECB(Mode):
    name = "ECB"

    validate_for_algorithm = _check_aes_key_length


print(ECB())

ERROR Cannot instantiate `ECB` because the following members are abstract: `validate_for_algorithm` [bad-instantiation]
 --> pyrefly_cryptography.py:3:16
  |
3 | print(modes.ECB())
  |                ^^
  |
 INFO 1 error