code: public static boolean equalsValue(final Object o1, final Object o2) {
          if (o1 == null) {
              return o2 == null;
          }
          return o1.equals(o2);
      }
docs: Return true if o1 equals (according to {@link Object#equals(Object)}) o2.
  Also returns true if o1 is null and o2 is null! Is safe on either o1 or o2 being null.