CLEAN_OP_CHANGED_STR = dict(
    autoremove="The following packages will be REMOVED",
    autoclean="Del ",
)

def cleanup(operation: str | None = None) -> bool:
    if operation not in frozenset(["autoremove", "autoclean"]):
        raise AssertionError(f"Bad operation: {operation}")
    # After the guard + raise, operation is narrowed to str by pyright.
    # Pyrefly still sees str | None and reports:
    #   Invalid key for TypedDict `<anonymous>`, got `None`
    return CLEAN_OP_CHANGED_STR[operation] in "some output"  # FP