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
return null;
			IJavaElement element= delta.getElement();
			if (element.getElementType() > IJavaElement.CLASS_FILE)
				return null;
			if (target.equals(element))
				return delta;
			IJavaElementDelta[] children= delta.getAffectedChildren();
			for (int i= 0; i < children.length; i++) {
				IJavaElementDelta d= findElement(target, children[i]);
				if (d != null)
					return d;
			}
			return null;
		}
	}
	/**
	 * Projection position that will return two foldable regions: one folding away
	 * the region from after the '/**' to the beginning of the content, the other
	 * from after the first content line until after the comment.
	 *
	 * @since 3.1
	 */
	private static final class CommentPosition extends Position implements IProjectionPosition {
		CommentPosition(int offset, int length) {
			super(offset, length);
		}
		/*
		 * @see org.eclipse.jface.text.source.projection.IProjectionPosition#computeFoldingRegions(org.eclipse.jface.text.IDocument)
		 */
		public IRegion[] computeProjectionRegions(IDocument document) throws BadLocationException {