Unclear meaning of DateTime for Gauges

[dv00d00]

There are two methods in StatsDMessageFormatter class which are using DateTime parameter

public string Gauge(double magnitude, string statBucket, DateTime timestamp)
{
    var stat = string.Format(InvariantCulture, "{0}{1}:{2}|g|@{3}", _prefix, statBucket, magnitude, timestamp.AsUnixTime());
    return Format(DefaultSampleRate, stat);
}

public string Gauge(long magnitude, string statBucket, DateTime timestamp)
{
    var stat = string.Format(InvariantCulture, "{0}{1}:{2}|g|@{3}", _prefix, statBucket, magnitude, timestamp.AsUnixTime());
    return Format(DefaultSampleRate, stat);
}

I was not able to find any reference to Unix timestamp in statsd docs

https://github.com/b/statsd_spec#gauges
https://statsd.readthedocs.io/en/v3.3/types.html#gauges
https://github.com/etsy/statsd/blob/master/docs/metric_types.md#gauges

Also this paragraph

The StatsClient.gauge() method also support the rate parameter to sample data back to the statsd server, but use it with care, especially with gauges that may not be updated very often.

Am I missing something?

[slang25]

Agreed, it looks weird. Can't see any real justification in the (very old) commit that added it: 63c1a45

[AnthonySteele]

This is almost certainly unused, and not matched by similar methods for increment / timer etc.
Suggest that we remove it for the next major version?

[martincostello]

I'd concur that we could drop it as part of 4.0.0.