def _findSamesetProteins(protToPeps, proteins=None):
    proteins = viewkeys(protToPeps) if proteins is None else proteins
    equalEvidence = ddict(set)
    for protein in proteins:
        peptides = protToPeps[protein]
        equalEvidence[tuple(sorted(peptides))].add(protein)
    equalProteins = list()
    for proteins in viewvalues(equalEvidence):
        if len(proteins) > 1:
            equalProteins.append(tuple(sorted(proteins)))
    return equalProteins