def lookup_annotype_converter(cls, anno):
        # type: (Anno) -> Type[VMeta]
        """Look up a vmeta based on an Anno"""
        if hasattr(anno.typ, "__bases__"):
            # This is a proper type
            bases = inspect.getmro(anno.typ)
        else:
            # This is a numpy dtype
            bases = [anno.typ]
        for typ in bases:
            key = (typ, bool(anno.is_array), bool(anno.is_mapping))
            try:
                return cls._annotype_lookup[key]
            except KeyError:
                pass
        raise KeyError(anno)
Look up a vmeta based on an Anno