/** Creates the nested deltas for an opened element. */
 public void opened(IModelElement element) {
   ModelElementDelta delta = new ModelElementDelta(element);
   delta.changed(F_OPENED);
   insertDeltaTree(element, delta);
 }
 /** Mark this delta as a fine-grained delta. */
 public void fineGrained() {
   changed(F_FINE_GRAINED);
 }
 /** Creates the nested deltas for a closed element. */
 public void closed(IModelElement element) {
   ModelElementDelta delta = new ModelElementDelta(element);
   delta.changed(F_CLOSED);
   insertDeltaTree(element, delta);
 }
 /**
  * Creates the nested deltas resulting from a change operation. Convenience method for creating
  * change deltas. The constructor should be used to create the root delta and then a change
  * operation should call this method.
  */
 public ModelElementDelta changed(IModelElement element, int changeFlag) {
   ModelElementDelta changedDelta = new ModelElementDelta(element);
   changedDelta.changed(changeFlag);
   insertDeltaTree(element, changedDelta);
   return changedDelta;
 }