мне нужно обфусцировать код с помощью proguard.
добавил в мавен

<plugin>
<groupId>com.pyx4me</groupId>
<artifactId>proguard-maven-plugin</artifactId>
<executions>
<execution>
<phase>package</phase>
<goals><goal>proguard</goal></goals>
</execution>
</executions>
<configuration>
<proguardVersion>4.0betta1</proguardVersion>
<libs>
<lib>${java.home}/lib/rt.jar</lib>
</libs>
</configuration>
</plugin>

при сборке mvn package выдает следующее

[INFO] Failed to resolve artifact.

Missing:
----------
1) net.sf.proguard:proguard:jar:4.0betta1

Try downloading the file manually from the project website.

Then, install it using the command:
mvn install:install-file -DgroupId=net.sf.proguard -DartifactId=proguard -Dversion=4.0betta1 -Dpackaging=jar -Dfile=/path/to/file

Alternatively, if you host your own repository you can deploy the file there:
mvn deploy:deploy-file -DgroupId=net.sf.proguard -DartifactId=proguard -Dversion=4.0betta1 -Dpackaging=jar -Dfile=/path/to/file -Durl= -DrepositoryId=[id]

Path to dependency:
1) Product:Product:jar:1.0
2) net.sf.proguard:proguard:jar:4.0betta1

----------
1 required artifact is missing.

for artifact:
Product:Product:jar:1.0

from the specified remote repositories:
central ( http://repo1.maven.org/maven2)

как сделать чтобы обфусцировать при запуске mvn package ?