public ArrayList<Protein> getDiscretes() {
   if (discretes == null) {
     categorizeProteins();
   }
   return discretes;
 }
 public ArrayList<Protein> getDifferentiables() {
   if (differentiables == null) {
     categorizeProteins();
   }
   return differentiables;
 }
 public ArrayList<Protein> getSubsumables() {
   if (subsumables == null) {
     categorizeProteins();
   }
   return subsumables;
 }
 public ArrayList<Protein> getSupersets() {
   if (supersets == null) {
     categorizeProteins();
   }
   return supersets;
 }
 public ArrayList<Protein> getEquivalents() {
   if (equivalents == null) {
     categorizeProteins();
   }
   return equivalents;
 }
 public ArrayList<Protein> getCountables() {
   if (countables == null) {
     categorizeProteins();
   }
   return countables;
 }