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: unique_name_values.rs
    path of file: ./repos/fuels-rs/packages/fuels-macros/src/parse_utils
    
    the code of the file until where you have to start completion: use std::collections::HashMap;

use fuels_code_gen::utils::ident;
use itertools::Itertools;
use proc_macro2::{Ident, Span, TokenStream};
use syn::{
    parse::Parser, punctuated::Punctuated, spanned::Spanned, Error, Expr, Lit, LitStr,
    MetaNameValue,
};

use crate::parse_utils::{validate_no_duplicates, ErrorsExt};

#[derive(Debug)]
pub struct UniqueNameValues {
    span: S
    
    fn cannot_get_lit_str_if_type_is_wrong() -> syn::Result<()> {
        let name_values = extract_name_values(quote! {SomeCommand(name=true)})?;

        let err = name_values
            .get_as_lit_str("name")
            .expect_err("should have failed");

        assert_eq!(
            err.to_string(),
            "expected the attribute 'name' to have a string value"
        );

        Ok(())
    }