Q: Is process_fn branch in #[trusted_relayer] needed?

[olga24912]

pub fn trusted_relayer(args: TokenStream, input: TokenStream) -> TokenStream {
    let input_clone: proc_macro2::TokenStream = input.clone().into();

    if is_impl_block(&input_clone) {
        if args.is_empty() {
            process_impl_block_guard_only(input)
        } else {
            process_impl_block(args, input)
        }
    } else {
        if !args.is_empty() {
            return syn::Error::new(
                proc_macro2::Span::call_site(),
                "`#[trusted_relayer]` on methods does not accept arguments",
            )
            .to_compile_error()
            .into();
        }
        process_fn(input)
    }
}

Why do we need the else branch with process_fn? Both process_impl_block and process_impl_block_guard_only already inject guards into all methods marked with #[trusted_relayer] inside the impl block.