code: 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