Bug 63389 [projection] Do we need a folding region for the top-level type?
The Java editor is currently defining a folding region for the top-level type. I couldn't find a good use of this folding region and in particular it leads to some visual instability when hovering in the vertical rule in between methods. Therefore I suggest to not add this folding region.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/folding/DefaultJavaFoldingStructureProvider.java
fFirstType= null;
			fHasHeaderComment= false;
			if (fEditor instanceof CompilationUnitEditor) {
				IWorkingCopyManager manager= JavaPlugin.getDefault().getWorkingCopyManager();
				fInput= manager.getWorkingCopy(fEditor.getEditorInput());
			} else if (fEditor instanceof ClassFileEditor) {
				IClassFileEditorInput editorInput= (IClassFileEditorInput) fEditor.getEditorInput();
				fInput= editorInput.getClassFile();
			}
			if (fInput != null) {
				ProjectionAnnotationModel model= (ProjectionAnnotationModel) fEditor.getAdapter(ProjectionAnnotationModel.class);
				if (model != null) {
					fCachedModel= model;
					if (fInput instanceof ICompilationUnit) {
						ICompilationUnit unit= (ICompilationUnit) fInput;
						synchronized (unit) {
							try {
								unit.reconcile(ICompilationUnit.NO_AST, false, null, null);
							} catch (JavaModelException x) {
							}
						}
					}
					Map additions= computeAdditions((IParent) fInput);
					/*
					 *  Minimize the events being sent out - as this happens in the
					 *  UI thread merge everything into one call.
					 */
					List removals= new LinkedList();
					Iterator existing= model.getAnnotationIterator();
					while (existing.hasNext())