#[derive(Debug)]
pub struct Context<'a, S, E, Ctx> {
pub from: &'a S,
pub to: &'a S,
pub event: &'a E,
pub context: &'a Ctx,
}
#[derive(Debug)]
pub struct ContextMut<'a, S, E, Ctx> {
pub from: &'a S,
pub to: &'a S,
pub event: &'a E,
pub context: &'a mut Ctx,
}