docs: public void setDerefSet(ValueNumber vn, Set<Location> derefSet) {
          if (UnconditionalValueDerefAnalysis.DEBUG) {
              System.out.println("Adding dereference of " + vn + " for # " + System.identityHashCode(this) + " to " + derefSet);
          }
          valueNumbersUnconditionallyDereferenced.set(vn.getNumber());
  
          Set<Location> derefLocationSet = getDerefLocationSet(vn);
          derefLocationSet.clear();
          derefLocationSet.addAll(derefSet);
      }