The event is cancelable
cancel
returns whether the event has been intercepted and stopped
If the value becomes "true", it returns/exits from the method, instantiating the interface
Optional
eventOptional Represents the original event, that has triggered the expansion/collapse
Returns the state of the row after the operation has ended Indicating whether the row is being expanded (true) or collapsed (false)
Optional
ownerProvides reference to the owner component.
Represents the ID of the row that emitted the event (which state is changed)
Represents event arguments related to the row's expansion state being changed in a grid