From 926d49744b0c9d4a6713878d1b9ab50631555d72 Mon Sep 17 00:00:00 2001
From: Duncan Smart
Fired when a choice is being cleared in the dropdown, but before any modification has been made to the selection.
+ This event is used to allow the user to reject the clear by calling event.preventDefault()
For the clear button to be visible the allowClear
option needs to be true
.