storage/remote/codec.go
func (c *concreteSeriesIterator) At() (t int64, v float64) {
	s := c.series.samples[c.cur]
	return s.Timestamp, s.Value
}
func (c *concreteSeriesIterator) At() (t int64, v float64) {
	s := c.series.samples[c.cur]
	return s.Timestamp, s.Value
}
// At implements storage.SeriesIterator.