Macro wrap_request_context_handler 

macro_rules! wrap_request_context_handler {
    ($ vis : vis struct $ name : ident ; impl RequestContextHandler { $ ($ (# [$ attrs_name : meta]) * fn $ method_name : ident (& $ self : ident $ (, $ arg_name : ident : $ arg_type : ty) * $ (,) ?) $ (-> $ return_type : ty) ? { $ ($ body : tt) * }) * }) => { ... };
    ($ vis : vis struct $ name : ident $ (< $ ($ generic_type : ident : $ first_generic_type_bound : tt $ (+ $ generic_type_bound : tt) *) , + $ (,) ? >) ? { $ ($ field_vis : vis $ field_name : ident : $ field_type : ty) , * $ (,) ? } impl RequestContextHandler { $ ($ (# [$ attrs_name : meta]) * fn $ method_name : ident (& $ self : ident $ (, $ arg_name : ident : $ arg_type : ty) * $ (,) ?) $ (-> $ return_type : ty) ? { $ ($ body : tt) * }) * }) => { ... };
}

Implement the WrapRequestContextHandler trait for the specified struct. You can declare more members for your struct, and in the impl RequestContextHandler block you can override default methods implemented by the ImplRequestContextHandler trait.

Example

wrap_request_context_handler! {
    struct MyRequestContextHandler {
        payload: String,
    }

    impl RequestContextHandler {
        // ...
    }
}

fn make_my_struct() -> RequestContextHandler {
    MyRequestContextHandler::new("payload".to_string())
}