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: united_kingdom.rs
    path of file: ./repos/RustQuant/src/time/countries/europe
    
    the code of the file until where you have to start completion: // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
// RustQuant: A Rust library for quantitative finance tools.
// Copyright (C) 2022-2024 https://github.com/avhz
// Dual licensed under Apache 2.0 and MIT.
// See:
//      - LICENSE-APACHE.md
//      - LICENSE-MIT.md
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    
    fn is_holiday(&self, date: Date) -> bool {
        let (y, m, d, wd, yd, em) = unpack_date(date, false);

        if (
            // New Year's Day (possibly moved to Monday)
            ((d == 1 || ((d == 2 || d == 3) && wd == Weekday::Monday)) && m == Month::January)
             // Good Friday
             || (yd == em - 3)
             // Easter Monday
             || (yd == em)
             // Bank Holidays
             || self.is_bank_holiday(d, wd, m, y)
             // Christmas (possibly moved to Monday or Tuesday)
             || ((d == 25 || (d == 27 && (wd == Weekday::Monday || wd == Weekday::Tuesday))) && m == Month::December)
             // Boxing Day (possibly moved to Monday or Tuesday)
             || ((d == 26 || (d == 28 && (wd == Weekday::Monday || wd == Weekday::Tuesday))) && m == Month::December)
             // December 31st, 1999 only
             || (d == 31 && m == Month::December && y == 1999)
        ) {
            return true;
        }

        false
    }