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/bottlerocket/sources/api/netdog/systemd-derive/src
    
    the code of the file until where you have to start completion: /*!

A macro to serialize structs to `systemd` unit file format

## Description

The `SystemdUnit` and `SystemdUnitSection` macros can be used to serialize structs representing
    
pub fn derive_systemd_unit(input: TokenStream) -> TokenStream {
    // Parse the AST and "deserialize" into SystemdUnit
    let ast = parse_macro_input!(input as DeriveInput);
    let n =
        SystemdUnit::from_derive_input(&ast).expect("Unable to parse `systemd` macro arguments");

    quote!(#n).into()
}