* @param busNumber bus number
* @return appropriate bus implementation
* @throws IOException thrown in case there is a problem opening bus file or bus number is not 0 or 1.
*/
public static I2CBus getBus(int busNumber) throws IOException {
I2CBus bus;
if (busNumber == 0) {
bus = bus0;
if (bus == null) {
bus = new I2CBusImpl("/dev/i2c-0");
bus0 = bus;