uncomment hdf reference
-# from .reference_hdf_zarr import HDFReferenceRecipe
+from .reference_hdf_zarr import HDFReferenceRecipe
from .xarray_zarr import XarrayZarrRecipe
-__all__ = ["XarrayZarrRecipe"] # , "HDFReferenceRecipe"]
+__all__ = ["XarrayZarrRecipe", "HDFReferenceRecipe"]
