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: lib.rs
    path of file: ./repos/criterion.rs/macro/src
    
    the code of the file until where you have to start completion: extern crate proc_macro;
use proc_macro::TokenStream;
use proc_macro2::{Ident, TokenTree};
use quote::quote_spanned;

#[proc_macro_attribute]
pub fn criterion(attr: TokenStream, item: TokenStream) -> TokenStream {
    let attr = proc_macro2::TokenStream::from(attr);
    let item = proc_macro2::TokenStream::from(item);

    let span = proc_macro2::Span::call_site();

    let init = if stream_length(attr.clone()) != 0 {
        attr
    }
    else {
        quote_spanned!(span=> criterion::Criterion::default())
    };

    let function_name = find_name(item.clone());

    
pub fn criterion(attr: TokenStream, item: TokenStream) -> TokenStream {
    let attr = proc_macro2::TokenStream::from(attr);
    let item = proc_macro2::TokenStream::from(item);

    let span = proc_macro2::Span::call_site();

    let init = if stream_length(attr.clone()) != 0 {
        attr
    }
    else {
        quote_spanned!(span=> criterion::Criterion::default())
    };

    let function_name = find_name(item.clone());
    let wrapped_name = Ident::new(&format!("criterion_wrapped_{}", function_name.to_string()), span);

    let output = quote_spanned!(span=>
        #[test_case]
        pub fn #wrapped_name() {
            #item

            let mut c = #init.configure_from_args();
            #function_name(&mut c);
        }
    );

    output.into()
}