code: private Map<String, Integer> getHypotheses(Collection<KamEdge> edges) {
          Map<String, Integer> controlCountMap =
                  getTranscriptionalControls(edges);
          Map<String, Integer> hypCountMap = new HashMap<String, Integer>();
          for (String hyp : controlCountMap.keySet()) {
              if (controlCountMap.get(hyp) >= 4) {
                  hypCountMap.put(hyp, controlCountMap.get(hyp));
              }
          }
          return hypCountMap;
      }
docs: returns nodes with 4+ causal downstream to rnaAbundance() nodes.
  @param edges
  @return