def short_id(id64: int) -> int:
    """Given a 64-bit id, make a shorter 16-bit one."""
    id16 = 0
    for offset in range(0, 64, 16):
        id16 ^= id64 >> offset
    return id16 & 0xFFFF
Given a 64-bit id, make a shorter 16-bit one.
coverage/debug.py