docs: private MonthAdapter.CalendarDay findAccessibilityFocus() {
          final int childCount = getChildCount();
          for (int i = 0; i < childCount; i++) {
              final View child = getChildAt(i);
              if (child instanceof MonthView) {
                  final MonthAdapter.CalendarDay focus = ((MonthView) child).getAccessibilityFocus();
                  if (focus != null) {
                      if (Build.VERSION.SDK_INT == Build.VERSION_CODES.JELLY_BEAN_MR1) {
                          // Clear focus to avoid ListView bug in Jelly Bean MR1.
                          ((MonthView) child).clearAccessibilityFocus();
                      }
                      return focus;
                  }
              }
          }
  
          return null;
      }