A Cache Element, consisting of a key, value and attributes.
From ehcache-1.2, Elements can have keys and values that are Serializable or Objects. To preserve backward compatibility, special accessor methods for Object keys and values are provided: {@link #getObjectKey()} and{@link #getObjectValue()}. If placing Objects in ehcache, developers must use the new getObject... methods to avoid CacheExceptions. The get... methods are reserved for Serializable keys and values.
@author Greg Luck
@version $Id: Element.java 744 2008-08-16 20:10:49Z gregluck $