code: func (h *Histogram) RecordValue(v int64) error {
  	h.rw.Lock()
  	defer h.rw.Unlock()
  
  	err := h.hist.Current.RecordValue(v)
  	if err != nil {
  		return Error{h.name, err}
  	}
  	return nil
  }
docs: // RecordValue records the given value, or returns an error if the value is out
  // of range.
  // Returned error values are of type Error.