code: def lookup_annotype_converter(cls, anno):
          # type: (Anno) -> Type[VMeta]
          
          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)
docs: Look up a vmeta based on an Anno