def METHOD_NAME( refs, qrys ):
    for ref_mol_id in refs:
        ## problem if this doesn't exist at all
        if ref_mol_id not in qrys:
            raise Exception("ERROR: reference molecule ID ({0}) not found in qry VCF".format(ref_mol_id))
        ## check each SNP position
        for ref_snp_coord in refs[ref_mol_id]:
            ref_snp = refs[ref_mol_id][ref_snp_coord]
            ## informative if this SNP position isn't in the qry set at all
            if ref_snp_coord not in qrys[ref_mol_id]:
                ref_snp['inf'] = True
                #print("DEBUG: {0}:{1} SNP informative because not found in qry".format(ref_mol_id, ref_snp_coord) )
            ## informative if both have a SNP in the same coordinate but with different alleles
            elif not have_shared_allelic_variation(ref_snp['alt'], qrys[ref_mol_id][ref_snp_coord]['alt']):
                ref_snp['inf'] = True
                #print("DEBUG: {0}:{1} SNP informative because variant allele in qry (ref:{2} vs. qry:{3})".format( \
                #        ref_mol_id, ref_snp_coord, ref_snp['alt'], qrys[ref_mol_id][ref_snp_coord]['alt']) )