Bug 28575 Hierarchy view updates items twice [type hierarchy]
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/typehierarchy/TypeHierarchyViewPart.java
Object elem= selected.get(i);
					if (elem instanceof IType && !types.contains(elem)) {
						types.add(elem);
					}
				}
				if (types.size() == 1) {
					fSelectedType= (IType) types.get(0);
					updateMethodViewer(fSelectedType);
				} else if (types.size() == 0) {
					
				}
				if (nSelected == 1) {
					revealElementInEditor(selected.get(0), getCurrentViewer());
				}
			} else {
				fSelectedType= null;
				updateMethodViewer(null);
			}
		}
	}
	
	private void revealElementInEditor(Object elem, Viewer originViewer) {
		
		
		if (getSite().getPage().getActivePart() != this) {
			return;
		}
		
		if (fSelectionProviderMediator.getViewerInFocus() != originViewer) {
			return;