Bug 156883 [Viewers] enhancements to ILazyTreeContentProvider
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
return getContentProvider() instanceof ITreePathContentProvider;
	}
	/**
	 * Inserts the given element as a new child element of the given parent
	 * element at the given position. If this viewer has a sorter, the position
	 * is ignored and the element is inserted at the correct position in the
	 * sort order.
	 * <p>
	 * This method should be called (by the content provider) when elements have
	 * been added to the model, in order to cause the viewer to accurately
	 * reflect the model. This method only affects the viewer, not the model.
	 * </p>
	 * 
	 * @param parentElementOrTreePath
	 *            the parent element, or the tree path to the parent
	 * @param element
	 *            the element
	 * @param position
	 *            a 0-based position relative to the model, or -1 to indicate
	 *            the last position
	 * 
	 * @since 3.2
	 */
	public void insert(Object parentElementOrTreePath, Object element,
			int position) {
		Assert.isNotNull(parentElementOrTreePath);
		Assert.isNotNull(element);
		if (getComparator() != null || hasFilters()) {
			add(parentElementOrTreePath, new Object[] { element });
			return;