def pretty_protocol_version(version: int) -> str:
    """
    Return a user-friendly representation of a protocol version.
    """
    try:
        version_name = QuicProtocolVersion(version).name
    except ValueError:
        version_name = "UNKNOWN"
    return f"0x{version:08x} ({version_name})"

    Return a user-friendly representation of a protocol version.
    
src/aioquic/quic/packet.py