private void markAndTraverse(OopHandle handle) {
   try {
     markAndTraverse(heap.newOop(handle));
   } catch (AddressException e) {
     System.err.println(
         "RevPtrs analysis: WARNING: AddressException at 0x"
             + Long.toHexString(e.getAddress())
             + " while traversing oop at "
             + handle);
   } catch (UnknownOopException e) {
     System.err.println(
         "RevPtrs analysis: WARNING: UnknownOopException for " + "oop at " + handle);
   }
 }