Eventhandlerreflex.event.EventHandlerAn event handler responds to an event to update the state.FieldsPropDescriptionfn: Any = NoneThe function to call in response to the event.state_full_name: str = ''The full name of the state class this event handler is attached to. Empty string means this event handler is a server side event.MethodsSignatureDescriptionget_parameters(self) -> collections.abc.Mapping[str, inspect.Parameter]Get the parameters of the function.