code: public static boolean allNull(final Object... o1s) {
          if (o1s != null && o1s.length > 0) {
              for (final Object o1 : o1s) {
                  if (o1 != null) {
                      return false;
                  }
              }
          }
          return true;
      }
docs: Return true if ALL of the given objects are null.