Macro rpc_success 

macro_rules! rpc_success {
    ($result:expr, $id:expr) => { ... };
    ($result:expr) => { ... };
}

Create a success response with a result value and optional ID

Examples:

// Success with ID
rpc_success!(42, Some(1))

// Success with ID from variable
rpc_success!(result, id)

// Success without ID
rpc_success!({"status": "ok"})