1 <p> This class inherits <code>equals(Object)</code> from an abstract
2 superclass, and <code>hashCode()</code> from
3 <code>java.lang.Object</code> (which returns
4 the identity hash code, an arbitrary value assigned to the object
5 by the VM). Therefore, the class is very likely to violate the
6 invariant that equal objects must have equal hashcodes.</p>
8 <p>If you don't want to define a hashCode method, and/or don't
9 believe the object will ever be put into a HashMap/Hashtable,
10 define the <code>hashCode()</code> method
11 to throw <code>UnsupportedOperationException</code>.</p>