Function event_loop_future_option 

pub fn event_loop_future_option<T: 'static>(
    future: impl Future<Output = T> + 'static,
    write: WriteSignal<Option<T>>,
    write_finished: WriteSignal<bool>,
    trigger: ExtSendTrigger,
)

Execute a future on the main event loop by polling, for Option signals. The future does not need to be Send.