def write_cache_time(f, t):
    if isinstance(t, int):
        t = (t, 0)
    elif isinstance(t, float):
        (secs, nsecs) = divmod(t, 1.0)
        t = (int(secs), int(nsecs * 1000000000))
    elif not isinstance(t, tuple):
        raise TypeError(t)
    f.write(struct.pack(">LL", *t))
Get an ordered list of this :class:`TableSet`'s column names.
dataset/ETHPy150Open natestedman/Observatory/observatory/lib/dulwich/index.py/write_cache_time--crossover with--dataset/ETHPy150Open wireservice/agate/agate/tableset/__init__.py/TableSet.column_names