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: read_bytes_ext.rs
    path of file: ./repos/databend/src/common/io/tests/it/cursor_ext
    
    the code of the file until where you have to start completion: // Copyright 2022 Datafuse Labs.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance wi
    
fn test_read_ext() {
    let mut cursor = Cursor::new("1 bytes   helloworld".as_bytes());

    cursor.ignore_byte(b'1');
    cursor.ignore_white_spaces();
    let bs = cursor.remaining_slice();
    assert_eq!(String::from_utf8_lossy(bs), "bytes   helloworld");

    let mut vec = vec![];
    cursor.until(b's', &mut vec);
    assert_eq!(
        String::from_utf8_lossy(cursor.remaining_slice()),
        "   helloworld"
    );
    assert_eq!(String::from_utf8_lossy(&vec), "bytes".to_string());

    let spaces = cursor.ignore_white_spaces();
    assert!(spaces);
    assert_eq!(
        String::from_utf8_lossy(cursor.remaining_slice()),
        "helloworld"
    );

    let mut cursor = Cursor::new("1 bytes   helloworld".as_bytes());

    cursor.ignore_byte(b'1');
    cursor.ignore_white_spaces();
    let bs = cursor.remaining_slice();
    assert_eq!(String::from_utf8_lossy(bs), "bytes   helloworld");
}