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: serialize.rs
    path of file: ./repos/erg/crates/erg_common
    
    the code of the file until where you have to start completion: //! オブジェクトのシリアライズ(バイナリ列化)のためのユーティリティーを定義・実装する
use std::time::{SystemTime, UNIX_EPOCH};

use crate::impl_display_from_debug;
use crate::python_util::PythonVersion;
use crate::Str;

/* Python bytecode specification */
// 0~3 byte: magic number
// 4~7 byte: padding (0;4)
// 8~B byte: UNIX timestamp
// C~F byte: padding (0;4)
// 10~ byte: marshalled code objects
// the unary magic number of Python bytecode
// magic number = version number (2byte) + 168624128 (0x0A0D0000)
// e.g. Python 3.7.4 b5's version number: 3394
// -> magic number: 0x0AD0D042
// -> bytes (little endian): 42 0D 0D 0A
pub const fn get_magic_num_bytes(python_ver: u32) -> [u8; 4] {
    pub const PREFIX: u32 = 0xA0D0000;
    (PREFIX | python_ver).to_le_bytes()
}

pub const fn get_magic_num_from_bytes(bytes: &[u8; 4]) -> u32 {
    u32::from_le_bytes([bytes[0], bytes[1], 0, 0])
}

pub const fn get_ver_from_magic_num(magic_num: u32) -> PythonVersion {
    match magic_num {
        3360..=3379 => PythonVersion::new(3, Some(6), Some(0)),
        3390..=3394 => PythonVersion::new(3, Some(7), Some(0)),
        3400..=3413 => PythonVersion::new(3, Some(8), Some(0)),
        3420..=3425 => PythonVersion::ne
    
    fn from(item: u8) -> Self {
        match item as char {
            'i' | '\u{00E9}' => Self::Int32,
            'I' => Self::Int64,
            'l' => Self::Long,
            'f' => Self::Float,
            'g' => Self::BinFloat,
            'x' => Self::Complex,
            'y' => Self::BinComplex,
            'T' => Self::True,
            'F' => Self::False,
            'N' => Self::None,
            'S' => Self::StopIter,
            's' | '\u{00F3}' => Self::Str,
            'Z' | '\u{00DA}' => Self::ShortAsciiInterned,
            'z' | '\u{00FA}' => Self::ShortAscii,
            'u' => Self::Unicode,
            't' => Self::Interned,
            '(' | '\u{00A8}' => Self::Tuple,
            ')' | '\u{00A9}' => Self::SmallTuple,
            'c' | '\u{00E3}' => Self::Code,
            'b' => Self::Builtin,
            'n' => Self::Nat,
            /*'\u{00F9}' => DataTypeUnaryOp::ErgInt8,
            '\u{00FA}' => DataTypeUnaryOp::ErgInt32,
            '\u{00FB}' => DataTypeUnaryOp::ErgFloat32,
            '\u{00FC}' => DataTypeUnaryOp::ErgStr,
            '\u{00FD}' => DataTypeUnaryOp::ErgFloat,
            '\u{00FE}' => DataTypeUnaryOp::HeapArray,
            '\u{00FF}' => DataTypeUnaryOp::NumArray,*/
            _ => Self::Illegal,
        }
    }