Method verify_duplicate_base_classes

mypy/semanal.py:2816–2820

(self, defn: ClassDef)

        return not cycle

    def verify_duplicate_base_classes(self, defn: ClassDef) -> bool:
        dup = find_duplicate(defn.info.direct_base_classes())
        if dup:
            self.fail(f'Duplicate base class "{dup.name}"', defn)
        return not dup

    def is_base_class(self, t: TypeInfo, s: TypeInfo) -> bool:
        """Determine if t is a base class of s (but do not use mro)."""