Return molecule that explicit hydrogens removed
    TODO: this query function should be renamed to "explicitHs_removed"

def make_Hs_implicit(original_mol, keep_stereo=True):
    """Return molecule that explicit hydrogens removed
    TODO: this query function should be renamed to "explicitHs_removed"
    """
    mol = clone(original_mol)
    mol.descriptors.clear()  # Reset descriptor
    to_remove = set()
    for i, nbrs in mol.neighbors_iter():
        if mol.atom(i).symbol == "H":  # do not remove H2
            continue
        for nbr, bond in nbrs.items():
            if mol.atom(nbr).symbol == "H" and \
                    not (bond.order == 1 and bond.type and keep_stereo):
                to_remove.add(nbr)
    for r in to_remove:
        mol.remove_atom(r)
    assign_descriptors(mol)
    return mol