Bug 164989 [Viewers] ColumnViewer#getColumnViewerOwner() doesn't respects column count
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
public TreeViewer(Tree tree) {
		super();
		this.tree = tree;
		hookControl(tree);
		treeEditor = new TreeEditor(tree);
		initTreeViewerImpl();
	}
	/*
	 * (non-Javadoc) Method declared in AbstractTreeViewer.
	 */
	protected void addTreeListener(Control c, TreeListener listener) {
		((Tree) c).addTreeListener(listener);
	}
	/**
	 * Cancels a currently active cell editor. All changes already done in the
	 * cell editor are lost.
	 * 
	 * @since 3.1
	 */
	public void cancelEditing() {
		treeViewerImpl.cancelEditing();
	}
	/*
	 * (non-Javadoc) Method declared in AbstractTreeViewer.
	 */
	protected void doUpdateItem(final Item item, Object element) {
		if (!(item instanceof TreeItem)) {
			return;
		}
		TreeItem treeItem = (TreeItem) item;