pub trait JsonEventHandler {
    fn handle_event(&mut self,
                    handle: Handle,
                    asset_id: [u8; 16],
                    event: Value) -> Box<Future<Item=SysGraph, Error=Box<Error>>>;

    fn should_handle(&self, event_name: &str) -> bool;
}

let event_dispatcher = EtwEventDispatcher{
    handlers: vec![
        Box::new(EtwProcessCreateHandler {}) as Box<JsonEventHandler>,
        Box::new(EtwProcessStopHandler {}) as Box<JsonEventHandler>,
        Box::new(EtwFileCreateHandler {}) as Box<JsonEventHandler>,
        Box::new(EtwFileDeleteHandler {}) as Box<JsonEventHandler>,
    ],
    core: Core::new().unwrap()
};