def atom_transformers(encs):
    """
    Utility function intended to build a transformer dictionary that
    gets passed into the chem.node_feats() function.
    """
    tfm = {
        "atomic_num": None,
        "chiral_tag": encs["chiral_tag"],
        "formal_charge": int,
        "num_explicit_hs": int,
        "is_aromatic": int,
        # "implicit_valence": int,
        # "total_hydrogens": int,
    }
    return tfm