docs: public int setPageCount(final int num) {
          int diff = num - getCheckableCount();
          if (diff > 0) {
              addIndicatorChildren(diff);
          } else if (diff < 0) {
              removeIndicatorChildren(-diff);
          }
          if (mCurrentPage >=num ) {
              mCurrentPage = 0;
          }
          setCurrentPage(mCurrentPage);
          return diff;
      }