code: private int getUniqueGeneReference(Collection<KamNode> nodes) {
          //count all protienAbundance reference
          Set<String> uniqueLabels = new HashSet<String>();
          for (KamNode node : nodes) {
              if (node.getFunctionType() == FunctionEnum.PROTEIN_ABUNDANCE
                      && StringUtils.countMatches(node.getLabel(), "(") == 1
                      && StringUtils.countMatches(node.getLabel(), ")") == 1) {
                  uniqueLabels.add(node.getLabel());
              }
          }
  
          return uniqueLabels.size();
      }
docs: returns number unique gene reference
  @param edges
  @return