Bug 93400 LTK UI should provide official API for structural content in the preview page
org.eclipse.ltk.ui.refactoring/src/org/eclipse/ltk/internal/ui/refactoring/TextEditChangeElement.java
return fgChildren;
	}
	
	public boolean hasOneGroupCategory(List categories) {
		return fChangeGroup.getGroupCategorySet().containsOneCategory(categories);
	}
	
	public GroupCategorySet getGroupCategorySet() {
		return fChangeGroup.getGroupCategorySet();
	}
	
	private DefaultChangeElement getDefaultChangeElement() {
		ChangeElement element= getParent();
		while(!(element instanceof DefaultChangeElement) && element != null) {
			element= element.getParent();
		}
		return (DefaultChangeElement)element;
	}
	
	private static IRegion getTextRange(ChangeElement element) throws CoreException {
		if (element == null)
			return null;
		if (element instanceof PseudoLanguageChangeElement) {
			return ((PseudoLanguageChangeElement)element).getTextRange();
		} else if (element instanceof DefaultChangeElement) {
			return null;
		}
		return getTextRange(element.getParent());
	}
}