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: parser.rs
    path of file: ./repos/sozu/command/src
    
    the code of the file until where you have to start completion: use nom::{
    bytes::streaming::is_not,
    character::complete::char,
    combinator::map_res,
    error::{ErrorKind, FromExternalError},
    multi::many0,
    sequence::terminated,
    IResult,
};

#[derive(Debug)]
#[allow(dead_code)]
pub struct ParseError {
    kind: ErrorKind,
    serde_json_error: Option<serde_json::Error>,
}

impl FromExternalError<&[u8], serde_json::Error> for ParseError {
    fn from_external_error(
        _input: &[u8],
        kind: ErrorKind,
        se
    
    fn parse_several_worker_requests() {
        let requests = vec![
            WorkerRequest::new(
                "Some request".to_string(),
                RequestType::SaveState("/some/path".to_string()).into(),
            ),
            WorkerRequest::new(
                "Some other request".to_string(),
                RequestType::SubscribeEvents(SubscribeEvents {}).into(),
            ),
            WorkerRequest::new(
                "Yet another request".to_string(),
                RequestType::Status(Status {}).into(),
            ),
        ];

        let mut serialized_requests = String::new();

        for request in requests.iter() {
            serialized_requests += &serde_json::ser::to_string(&request).unwrap();
            serialized_requests.push('\0');
        }

        let bytes_to_parse = &serialized_requests.as_bytes();

        let parsed_requests = parse_several_requests(bytes_to_parse).unwrap();

        println!("parsed commands: {parsed_requests:?}");

        let empty_vec: Vec<u8> = vec![];

        assert_eq!(parsed_requests, (&empty_vec[..], requests))
    }