def _get_spatial_bounds(self):
        """Get the spatial bounds of the chunk.""" 
        # This should be a MultiRasterIO method
        with rasterio.open(self._mrio._get_template_for_given_resolution(self._mrio.dst_res, "path")) as src_layer:
            pass # later we need src_layer for src_layer.window_transform(win)
        win_transform = src_layer.window_transform(self._window)
        bounds = rasterio.windows.bounds(window=self._window,
                                         transform=win_transform,
                                         height=0, width=0)
        return bounds
Get the spatial bounds of the chunk.