code: func (c *Client) updateAdjustment(other *Coordinate, rttSeconds float64) {
  	if c.config.AdjustmentWindowSize == 0 {
  		return
  	}
  
  	// Note that the existing adjustment factors don't figure in to this
  	// calculation so we use the raw distance here.
  	dist := c.coord.rawDistanceTo(other)
  	c.adjustmentSamples[c.adjustmentIndex] = rttSeconds - dist
  	c.adjustmentIndex = (c.adjustmentIndex + 1) % c.config.AdjustmentWindowSize
  
  	sum := 0.0
  	for _, sample := range c.adjustmentSamples {
  		sum += sample
  	}
  	c.coord.Adjustment = sum / (2.0 * float64(c.config.AdjustmentWindowSize))
  }
docs: // updateAdjustment updates the adjustment portion of the client's coordinate, if
  // the feature is enabled. This assumes that the mutex has been locked already.