public/ckeditor/_source/plugins/selection/plugin.js
function()
		{
			var ranges = this.getRanges(),
				startNode = ranges[ 0 ].startContainer,
				endNode = ranges[ ranges.length - 1 ].endContainer;
			return startNode.getCommonAncestor( endNode );
		}
function()
		{
			var ranges = this.getRanges(),
				startNode = ranges[ 0 ].startContainer,
				endNode = ranges[ ranges.length - 1 ].endContainer;
			return startNode.getCommonAncestor( endNode );
		}
function ( ) { var ranges = this . getRanges ( ) , startNode = ranges [ 0 ] . startContainer , endNode = ranges [ ranges . length - 1 ] . endContainer ; return startNode . getCommonAncestor ( endNode ) ; }
Retrieves the common ancestor node of the first range and the last range.
@returns {CKEDITOR.dom.element} The common ancestor of the selection.
@example
var ancestor = editor.getSelection().<strong>getCommonAncestor()</strong>;
Retrieves the common ancestor node of the first range and the last range .