code: private static boolean equalsMayBeNull(Object obj1, Object obj2)
    {
      return (obj2 == obj1)
             || ((null != obj1) && (null != obj2) && obj2.equals(obj1));
    }
docs: Tell if two objects are equal, when either one may be null.
  If both are null, they are considered equal.
  
  @param obj1 A reference to the first object, or null.
  @param obj2 A reference to the second object, or null.
  
  @return true if the to objects are equal by both being null or
  because obj2.equals(obj1) returns true.