Support AT or GAT?

[Dengjianping]

The compiler reports this error when I add a GAT.

error: Only methods allowed in RPC traits
  --> src/rpc/mod.rs:12:5
   |
12 |     type Item<'a> where Self: 'a;

Not sure there's a plan to support it.

[niklasad1]

It's not supported yet, as the compiler says currently it's only allowed to add functions to the RPC trait i.e, not associated types.

Can you give an example what your trying to do and what's the benefit for jsonrpsee to support it? Thanks