dicates that the action must always have an empty element body, by a
 &lt;body-content&gt; entry of "empty", then the doStartTag() method must return SKIP_BODY.

 <p>
 Note that which methods are invoked after the doStartTag() depends on both the return value and on if the custom
 action element is empty or not in the JSP page, not on how it's declared in the TLD.

 <p>
 If SKIP_BODY is returned the body is not evaluated, and then doEndTag() is invoked.

 <p>
 If EVAL_BODY_INCLUDE is returned, and the custo