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: util.rs
    path of file: ./repos/rusoto/rusoto/core/src/proto/xml
    
    the code of the file until where you have to start completion: //! Tools for handling XML from AWS with helper functions for testing.
//!
//! Wraps an XML stack via traits.
//! Also provides a method of supplying an XML stack from a file for testing purposes.

use std::collections::HashMap;
use std::io;
use std::iter::Peekable;
use std::num::ParseIntError;
use xml;
use xml::reader::{EventReader, Events, ParserConfig, XmlEvent};
use xml::writer::EventWriter;

use crate::{error::RusotoError, request::HttpResponse};

/// generic Error for XML parsing
#[derive(Debug)]
pub struct XmlParseErr
    
    fn start_element_happy_path() {
        let mut file = File::open("test_resources/list_queues_with_queue.xml").unwrap();
        let mut body = String::new();
        let _size = file.read_to_string(&mut body);
        let my_parser = EventReader::new(body.as_bytes());
        let my_stack = my_parser.into_iter().peekable();
        let mut reader = XmlResponse::new(my_stack);

        // skip two leading fields since we ignore them (xml declaration, return type declaration)
        reader.next();
        reader.next();

        match start_element("ListQueuesResult", &mut reader) {
            Ok(_) => (),
            Err(_) => panic!("Couldn't find start element"),
        }
    }