src/main/java/org/codehaus/plexus/archiver/jar/JarArchiver.java
@SuppressWarnings( { "UnusedDeclaration" } )
    public void setFilesetmanifest( FilesetManifestConfig config )
    {
        filesetManifestConfig = config;
        mergeManifestsMain = FilesetManifestConfig.merge == config;

        if ( ( filesetManifestConfig != null ) && filesetManifestConfig != FilesetManifestConfig.skip )
        {

            doubleFilePass = true;
        }
    }
@SuppressWarnings( { "UnusedDeclaration" } )
    public void setFilesetmanifest( FilesetManifestConfig config )
    {
        filesetManifestConfig = config;
        mergeManifestsMain = FilesetManifestConfig.merge == config;

        if ( ( filesetManifestConfig != null ) && filesetManifestConfig != FilesetManifestConfig.skip )
        {

            doubleFilePass = true;
        }
    }
Behavior when a Manifest is found in a zipfileset or zipgroupfileset file.
Valid values are "skip", "merge", and "mergewithoutmain".
"merge" will merge all of manifests together, and merge this into any
other specified manifests.
"mergewithoutmain" merges everything but the Main section of the manifests.
Default value is "skip".
<p/>
Note: if this attribute's value is not "skip", the created jar will not
be readable by using java.util.jar.JarInputStream

@param config setting for found manifest behavior.