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: quickcheck_utils.rs
    path of file: ./repos/tools/crates/rome_js_formatter/src/utils
    
    the code of the file until where you have to start completion: /// Generates a string with only ascii chars
#[derive(Debug, Clone)]
pub struct AsciiString(String);

impl std::ops::Deref for AsciiString {
    type Target = str;

    fn deref(&self) -> &Self::Target {
        self.0.as_str()
    }
}

impl<'a> PartialEq<AsciiString> for &'a str {
    fn eq(&self, other: &AsciiString) -> bool {
        self == &other.0.as_str()
    }
}

impl std::fmt::Display for AsciiString {
    f
    
    fn arbitrary(g: &mut quickcheck::Gen) -> Self {
        let s = String::arbitrary(g);

        let mut ascii = String::new();
        for chr in s.chars() {
            if chr.is_ascii() {
                ascii.push(chr);
            } else {
                const WIDTH: u8 = b'~' - b' ';
                let chr = b' ' + (u8::arbitrary(g) % WIDTH);
                ascii.push(chr as char);
            }
        }

        assert!(ascii.is_ascii());

        Self(ascii)
    }