Bug 36981 call hierarchy: Search scope should be persisted
Search scope should be persisted when the platform shuts down or when the view is closed and reopened.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/callhierarchy/SearchScopeActionGroup.java
private IWorkingSet mWorkingSet;
        public SearchScopeWorkingSetAction(IWorkingSet workingSet) {
            super(workingSet.getName());
            setToolTipText(CallHierarchyMessages.getString("SearchScopeActionGroup.workingset.tooltip")); 
            WorkbenchHelp.setHelp(this, IJavaHelpContextIds.CALL_HIERARCHY_SEARCH_SCOPE_ACTION);
            this.mWorkingSet = workingSet;
        }
        public IJavaSearchScope getSearchScope() {
            return SearchEngine.createJavaSearchScope(getJavaElements(
                    mWorkingSet.getElements()));
        }
        /**
         *
         */
        public IWorkingSet getWorkingSet() {
            return mWorkingSet;
        }
        /**
         * @param adaptables