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: quality.rs
    path of file: ./repos/actix-web/actix-http/src/header/shared
    
    the code of the file until where you have to start completion: use std::fmt;

use derive_more::{Display, Error};

const MAX_QUALITY_INT: u16 = 1000;
const MAX_QUALITY_FLOAT: f32 = 1.0;

/// Represents a quality used in q-factor values.
///
/// The default value is equivalent to `q=1.0` (the [max](Self::MAX) value).
///
/// # Implementation notes
/// The quality value is defined as a number between 0.0 and 1.0 with three decimal plac
    
    fn display_output() {
        assert_eq!(Quality::ZERO.to_string(), "0");
        assert_eq!(Quality::MIN.to_string(), "0.001");
        assert_eq!(Quality::MAX.to_string(), "1");

        assert_eq!(q(0.0).to_string(), "0");
        assert_eq!(q(1.0).to_string(), "1");
        assert_eq!(q(0.001).to_string(), "0.001");
        assert_eq!(q(0.5).to_string(), "0.5");
        assert_eq!(q(0.22).to_string(), "0.22");
        assert_eq!(q(0.123).to_string(), "0.123");
        assert_eq!(q(0.999).to_string(), "0.999");

        for x in 0..=1000 {
            // if trailing zeroes are handled correctly, we would not expect the serialized length
            // to ever exceed "0." + 3 decimal places = 5 in length
            assert!(q(x as f32 / 1000.0).to_string().len() <= 5);
        }
    }