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: integration_tests.rs
    path of file: ./repos/encore/tsparser/litparser-derive/tests
    
    the code of the file until where you have to start completion: use std::option;

use litparser_derive::LitParser;
use swc_common::errors::{ColorConfig, Handler};
use swc_common::input::StringInput;
use swc_common::sync::Lrc;
use swc_common::{FileName, SourceMap};
use swc_ecma_parser::lexer::Lexer;
use swc_ecma_parser::{Parser, Syntax};

use litparser::LitParser;

#[test]
fn test_parse() {
    #[derive(LitParser)]
    struct Foo {
        foo: String,
        bar: std::time::Duration,
    }

    let expr = parse(r#"{ foo: "foo", bar: "1h" }"#);
    let foo = Foo::parse_lit(&*expr).expect("failed to parse lit")
    
fn parse(src: &str) -> Box<swc_ecma_ast::Expr> {
    let cm: Lrc<SourceMap> = Default::default();
    let handler = Handler::with_tty_emitter(ColorConfig::Auto, true, false, Some(cm.clone()));

    let fm = cm.new_source_file(FileName::Custom("test.ts".into()), src.into());
    let lexer = Lexer::new(
        Syntax::Es(Default::default()),
        Default::default(),
        StringInput::from(&*fm),
        None,
    );

    let mut parser = Parser::new_from(lexer);

    for e in parser.take_errors() {
        e.into_diagnostic(&handler).emit();
    }

    parser.parse_expr().expect("failed to parse expr")
}