/**
  * Overlays value with problem annotation.
  *
  * @param value the value
  * @param problemAnnotation
  */
 private void setOverlay(Object value, ProblemAnnotation problemAnnotation) {
   if (value instanceof JavaMarkerAnnotation) {
     JavaMarkerAnnotation annotation = (JavaMarkerAnnotation) value;
     if (annotation.isProblem()) {
       annotation.setOverlay(problemAnnotation);
       fPreviouslyOverlaid.remove(annotation);
       fCurrentlyOverlaid.add(annotation);
     }
   } else {
   }
 }
 private void removeMarkerOverlays(boolean isCanceled) {
   if (isCanceled) {
     fCurrentlyOverlaid.addAll(fPreviouslyOverlaid);
   } else if (fPreviouslyOverlaid != null) {
     Iterator<Annotation> e = fPreviouslyOverlaid.iterator();
     while (e.hasNext()) {
       JavaMarkerAnnotation annotation = (JavaMarkerAnnotation) e.next();
       annotation.setOverlay(null);
     }
   }
 }