code: func (c *concreteSeriesIterator) Seek(t int64) bool {
  	c.cur = sort.Search(len(c.series.samples), func(n int) bool {
  		return c.series.samples[n].Timestamp >= t
  	})
  	return c.cur < len(c.series.samples)
  }
docs: // Seek implements storage.SeriesIterator.