0 - 1 of 1 tags for back button

Hi All,
I looked into this jira http://developer.teradata.com/viewpoint/reference/how-to-create-a-controller-for-a-refreshed-parameterized-page for inserting a back button arrow into my portlet. It says that I must include the following lines of code into the drilldown jsp.

<%@ taglib prefix="vp" uri="http://teradata.com/viewpoint-widgets"%>