docs: public static int[] getBusIds() throws IOException {
          Set<Integer> set = null;
          for (Path device: Files.newDirectoryStream(Paths.get("/sys/bus/i2c/devices"), "*")) {
              String[] tokens = device.toString().split("-");
              if (tokens.length == 2) {
                  if (set == null) {
                      set = new HashSet<Integer>();
                  }
                  set.add(Integer.valueOf(tokens[1]));
              }
          }
  
          int[] result = null;
          if (set != null) {
              int counter = 0;
              result = new int[set.size()];
              for (Integer value : set) {
                  result[counter] = value.intValue();
                  counter = counter + 1;
              }
          }
          return result;
      }