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 tpcp.hasChildren(path);
		}
		if (cp instanceof ITreeContentProvider) {
			ITreeContentProvider tcp = (ITreeContentProvider) cp;
			return tcp.hasChildren(element);
		}
		return false;
	}
	/**
	 * Return whether the given element is expandable.
	 * 
	 * @param item
	 *            the tree item for the element
	 * @param parentPath
	 *            the parent path if it is knwon or <code>null</code> if it
	 *            needs to be determines
	 * @param element
	 *            the element
	 * @return whether the given element is expandable
	 */
	private boolean isExpandable(Item item, TreePath parentPath, Object element) {
		if (isTreePathContentProvider()) {
			TreePath path;
			if (parentPath != null) {
				path = parentPath.createChildPath(element);
			} else {
				path = getTreePathFromItem(item);
			}
			ITreePathContentProvider cp = (ITreePathContentProvider) getContentProvider();