code: public static boolean equal(Object thisObject, Object thatObject) {
          return thisObject == null ? thatObject == null : thisObject.equals(thatObject);
      }
docs: Compares two objects. This method is careful about <code>null</code> values.
  @param thisObject One object
  @param thatObject Other object
  @return <code>true</code> if the one object equals the other object; <code>false</code> otherwise