def _setattr_dict(self, name: str, value: Any) -> None:
        """Deprecated third party subclass (see ``__init_subclass__`` above)"""
        object.__setattr__(self, name, value)
        if name in self.__dict__:
            # Custom, non-slotted attr, or improperly assigned variable?
            warnings.warn(
                f"Setting attribute {name!r} on a {type(self).__name__!r} object. Explicitly define __slots__ "
                "to suppress this warning for legitimate custom attributes and "
                "raise an error when attempting variables assignments.",
                FutureWarning,
                stacklevel=2,
            )
Deprecated third party subclass (see ``__init_subclass__`` above)
xarray/core/common.py