code: public static Map<String, String> getEvidences(ProbabilisticNetwork bn) {
  
          HashMap<String, String> evidences = new HashMap<String, String>();
          for (Node n : bn.getNodes()) {
              ProbabilisticNode pn = (ProbabilisticNode) n;
              if (pn.hasEvidence()) {
                  evidences.put(pn.getName(), pn.getStateAt(pn.getEvidence()));
              }
          }
          return evidences;
      }
docs: Return all current evidences in the BN
  
  @param bn
  @return