checkContainedInExpandedNode = function(oNode, oBreaker) {
					if (aRelevantExpandedAfterSelectAllNodes.indexOf(oNode) !== -1) {
						iNumberOfVisibleDeselectedNodes--;
						oBreaker.broken = true;
					}
				}
Returns the number of selected nodes.

@returns {int} number of selected nodes.

@private
@ui5-restricted sap.ui.table.plugins.BindingSelection