OnStateChange() in Vaadin

Whenever a single property of our widget changes, onStateChange() is automatically invoked by the framework. But, how can we uniquely identify, which property of the widget state has changed?? Is there a way for it through the framework??
Or we need to refresh the entire DOM, even if a single property changes? Or Do I have to find a work around??

Please let me know.

The StateChangeEvent instance passed as a parameter to onStateChanged has methods for getting the changed properties or checking whether a given property has changed.

Oh, and there’s also addStateChangeHandler(String property, StateChangeHandler handler).