How to use the tobler.area_weighted._slow_area_interpolate function in tobler

allocate_total=allocate_total,
            )

        elif weights_method == "land_type_area":
            try:

                area_tables_raster_fitted = area_tables_raster(
                    source_df,
                    target_df.copy(),
                    raster_path=raster,
                    codes=codes,
                    force_crs_match=force_crs_match,
                )

                # In area_interpolate, the resulting variable has same lenght as target_df
                interpolation = _slow_area_interpolate(
                    source_df,
                    target_df.copy(),
                    extensive_variables=extensive_variables,
                    intensive_variables=intensive_variables,
                    allocate_total=allocate_total,
                    tables=area_tables_raster_fitted,
                )
            except IOError:
                raise IOError(
                    "You must have NLCD raster data installed locally to use the"
                    "`land_type_area` method. You can install it using the"
                    "`tobler.data.store_rasters()` function from the `tobler` package"
                )
        else:
            raise ValueError('weights_method must of one of ["area", "land_type_area"]')