use core::fmt;
pub trait CommBusBackend: 'static {
type Error: fmt::Display + fmt::Debug;
type Subscription: 'static;
fn subscribe(
event: &str,
callback: impl Fn(&str) + 'static,
) -> Result<Self::Subscription, Self::Error>;
fn call(event: &str, data: &str) -> Result<(), Self::Error>;
}