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