Bug 37464 call hierarchy: Should not use working copies
The call hierarchy should not use working copies of compilation units since these may go away (e.g. when an editor is closed).
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/callhierarchy/CallHierarchyViewPart.java
new SelectionProviderAdapter(fSelectionProviderMediator).addSelectionChangedListener(new StatusBarUpdater(
                slManager));
        getSite().setSelectionProvider(fSelectionProviderMediator);
        fClipboard= new Clipboard(parent.getDisplay());
        
        makeActions();
        fillViewMenu();
        fillActionBars();
        initOrientation();
        initCallMode();
        initImplementorsMode();
        if (fMemento != null) {
            restoreState(fMemento);
        }
        
        initDragAndDrop();      
    }
    /**
     * @param PAGE_EMPTY
     */
    private void showPage(int page) {
        if (page == PAGE_EMPTY) {
            fPagebook.showPage(fNoHierarchyShownLabel);
        } else {
            fPagebook.showPage(fHierarchyLocationSplitter);
        }
        enableActions(page != PAGE_EMPTY);
    }
    /**
     * @param b