Stores the supplied value for the specified style.
NOTE The current implementation always returns
null due to the use of BeanAdapter to set the the new
value. (BeanAdapter does not look up the previous value for
This also means that the logic determining whether to fire the the
event differs from other Pivot event firing code. The event will be
fired each time this method is executed, regardless of whether the
new value differs from the old value or not.
This behaviour may change in the future so should not be relied upon.