If you're taking a reference as parameter, you can mostly follow chapter 1.1 or chapter 1.2, however with one little exception:

Your implementation for State needs to work with every possible lifetime 'a. So it has to look like that:

impl<'a> State<&'a Argument, Error, Event> for MyState {}

It is very important that 'a is not bound on anything. If your state has a lifetime 'b, you have to declare two lifetimes for the State implementation, otherwise a given MyState<'a> would only implement State<'a> (but it has to implement State for every possible lifetime which Rust expresses with for<'a> State<'a>).