You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: context.rs
    path of file: ./repos/risingwave/src/expr/macro/src
    
    the code of the file until where you have to start completion: // Copyright 2024 RisingWave Labs
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this
    
    let new_user_fn = {
        let vis = user_fn.vis;
        let sig = user_fn.sig;
        quote! {
            #vis #sig {
                {#new_body}.map_err(Into::into)
            }
        }
    };