ANT task for p2.process.artifacts - adding md5 and artifacts sizes to p2 repository

p2-process-artifcats.xml

<?xml version="1.0" encoding="UTF-8"?>
<project name="project" default="p2-process-artifcats">

    <property name="p2.repo" value="file:///C:/tmp/161.1.9.RC0-20160407-200004" />

    <target name="p2-process-artifcats" description="adds md5 and artifacts sizes to p2 repository">
        <p2.process.artifacts repositorypath="${p2.repo}" />
    </target>

</project>

Hi, I develop an Eclipse RCP Application and I need to add md5 and artifact sizes to my p2 repository, but I don't know how to do this. Where do you put this file? Or the target tag? Thanks in advance.