def METHOD_NAME(self) -> None:
    classes = astroid.extract_node(
        """
    class classb(object): #@
        pass
    class CLASSA(object): #@
        pass
    class CLASSC(object): #@
        pass
    """
    )
    message = MessageTest(
        "invalid-name",
        node=classes[0],
        args=(
            "Class",
            "classb",
            "the `UP` group in the '(?:(?P<UP>[A-Z]+)|(?P<down>[a-z]+))$' pattern",
        ),
        confidence=HIGH,
        line=2,
        col_offset=0,
        end_line=2,
        end_col_offset=12,
    )
    with self.assertAddsMessages(message):
        cls = None
        for cls in classes:
            self.checker.visit_classdef(cls)
        if cls:
            self.checker.leave_module(cls.root)