Bug 161401 [Viewers] Tweak ColumnViewer-API
- Rename getRowPart(Point point) => getViewerRow() - Rename getCell(Point point) => getViewerCell() - Rename setViewerColumn(final int columnIndex, ViewerColumn viewer) => setupEditingSupport - Make setupEditingSupport() private no one from external needs to use this API to set the EditingSupport for an ViewerColumn
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/TreeViewer.java
*/
	protected void showItem(Item item) {
		getTree().showItem((TreeItem) item);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.viewers.AbstractTreeViewer#getChild(org.eclipse.swt.widgets.Widget,
	 *      int)
	 */
	protected Item getChild(Widget widget, int index) {
		if (widget instanceof TreeItem) {
			return ((TreeItem) widget).getItem(index);
		}
		if (widget instanceof Tree) {
			return ((Tree) widget).getItem(index);
		}
		return null;
	}
	protected void assertContentProviderType(IContentProvider provider) {
		if (provider instanceof ILazyTreeContentProvider
				|| provider instanceof ILazyTreePathContentProvider) {
			return;
		}
		super.assertContentProviderType(provider);
	}
	protected Object[] getRawChildren(Object parent) {
		if (contentProviderIsLazy) {
			return new Object[0];
		}