def _item_sources(self) -> Iterable[Mapping[Any, Any]]:
        """Places to look-up items for key-completion"""
        yield self.data_vars
        yield FilteredMapping(keys=self._coord_variables, mapping=self.coords)

        # virtual coordinates
        yield FilteredMapping(keys=self.dims, mapping=self)

        # immediate child nodes
        yield self.children
Places to look-up items for key-completion
xarray/core/datatree.py