code: func (b *BufferedSeriesIterator) Seek(t int64) bool {
  	t0 := t - b.buf.delta
  
  	// If the delta would cause us to seek backwards, preserve the buffer
  	// and just continue regular advancement while filling the buffer on the way.
  	if t0 > b.lastTime {
  		b.buf.reset()
  
  		b.ok = b.it.Seek(t0)
  		if !b.ok {
  			return false
  		}
  		b.lastTime, _ = b.Values()
  	}
  
  	if b.lastTime >= t {
  		return true
  	}
  	for b.Next() {
  		if b.lastTime >= t {
  			return true
  		}
  	}
  
  	return false
  }
docs: // Seek advances the iterator to the element at time t or greater.