func NewTimestampCollector() *TimestampCollector {
	return &TimestampCollector{
		Description: prometheus.NewDesc(
			"prometheus_sd_file_mtime_seconds",
			"Timestamp (mtime) of files read by FileSD. Timestamp is set at read time.",
			[]string{"filename"},
			nil,
		),
		discoverers: make(map[*Discovery]struct{}),
	}
}
func NewTimestampCollector() *TimestampCollector {
	return &TimestampCollector{
		Description: prometheus.NewDesc(
			"prometheus_sd_file_mtime_seconds",
			"Timestamp (mtime) of files read by FileSD. Timestamp is set at read time.",
			[]string{"filename"},
			nil,
		),
		discoverers: make(map[*Discovery]struct{}),
	}
}
// NewTimestampCollector creates a TimestampCollector.