code: func (d *ADS1x15Driver) ReadDifferenceWithDefaults(diff int) (value float64, err error) {
  	return d.ReadDifference(diff, d.DefaultGain, d.DefaultDataRate)
  }
docs: // ReadDifferenceWithDefaults reads the difference in V between 2 inputs. It uses the default gain and data rate
  // diff can be:
  // * 0: Channel 0 - channel 1
  // * 1: Channel 0 - channel 3
  // * 2: Channel 1 - channel 3
  // * 3: Channel 2 - channel 3