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/PseudoLanguageChangeElement.java
/**
	 * Adds the given <code>TextEditChangeElement<code> as a child to this 
	 * <code>PseudoJavaChangeElement</code>
	 * 
	 * @param child the child to be added
	 */
	public void addChild(TextEditChangeElement child) {
		doAddChild(child);
	}
	
	/**
	 * Adds the given <code>PseudoJavaChangeElement<code> as a child to this 
	 * <code>PseudoJavaChangeElement</code>
	 * 
	 * @param child the child to be added
	 */
	public void addChild(PseudoLanguageChangeElement child) {
		doAddChild(child);
	}
	
	private void doAddChild(ChangeElement child) {
		if (fChildren == null)
			fChildren= new ArrayList(2);
		fChildren.add(child);
	}
	
	private DefaultChangeElement getDefaultChangeElement() {
		ChangeElement element= getParent();
		while(!(element instanceof DefaultChangeElement) && element != null) {