+ @Override
+ public String toString() {
+ String s = "PropertyChange";
+ if (pair.first != null)
+ s += " (" + (leftSubject) + " , " + pair.first.getPredicate() + " , " + pair.first.getObject() + ")";
+ if (pair.second != null)
+ s += " (" + (rightSubject) + " , " + pair.second.getPredicate() + " , " + pair.second.getObject() + ")";
+ return s;
+ }
+