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/TreeViewer.java
*/
	public ICellModifier getCellModifier() {
		return treeViewerImpl.getCellModifier();
	}
	/*
	 * (non-Javadoc) Method declared in AbstractTreeViewer.
	 */
	protected Item[] getChildren(Widget o) {
		if (o instanceof TreeItem) {
			return ((TreeItem) o).getItems();
		}
		if (o instanceof Tree) {
			return ((Tree) o).getItems();
		}
		return null;
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.ColumnViewer#getColumnProperties()
	 */
	public Object[] getColumnProperties() {
		return treeViewerImpl.getColumnProperties();
	}
	/*
	 * (non-Javadoc) Method declared in Viewer.
	 */
	public Control getControl() {
		return tree;
	}