code: func (r *Adaptor) GetConnection(address int, bus int) (connection i2c.Connection, err error) {
  	if (bus < 0) || (bus > 1) {
  		return nil, fmt.Errorf("Bus number %d out of range", bus)
  	}
  
  	device, err := r.getI2cBus(bus)
  
  	return i2c.NewConnection(device, address), err
  }
docs: // GetConnection returns an i2c connection to a device on a specified bus.
  // Valid bus number is [0..1] which corresponds to /dev/i2c-0 through /dev/i2c-1.