Bug 158778 [Viewers] request for remove(parent, index) API on tree viewer
3.3 It would be helpful to have a 'remove(Object parent, int index)' method on the tree viewer to complement that 'replace(...)' and 'setChildCount(...)' APIs. The debug platform requires such a method to implement filtering in virtual tree views. Rather than performing a 'replace/remove' based on elements, the content provider can make one atomic call to remove an element at a specific index.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/AbstractTreeViewer.java
}
			}
		}
		return null;
	}
	/**
	 * Adds the given child elements to this viewer as children of the given
	 * parent element.
	 * <p>
	 * EXPERIMENTAL. Not to be used except by JDT. This method was added to
	 * support JDT's explorations into grouping by working sets, which requires
	 * viewers to support multiple equal elements. See bug 76482 for more
	 * details. This support will likely be removed in Eclipse 3.2 in favour of
	 * proper support for multiple equal elements.
	 * </p>
	 * 
	 * @param widget
	 *            the widget for the parent element
	 * @param parentElementOrTreePath
	 *            the parent element
	 * @param childElements
	 *            the child elements to add
	 * @since 3.1
	 */
	protected void internalAdd(Widget widget, Object parentElementOrTreePath,
			Object[] childElements) {
		Object parent;
		TreePath path;
		if (parentElementOrTreePath instanceof TreePath) {
			path = (TreePath) parentElementOrTreePath;