metadata = new Xpp3Dom( "metadata" );
addChild( metadata, "groupId", artifact.getGroupId() );
addChild( metadata, "artifactId", artifact.getArtifactId() );
Xpp3Dom versioning = new Xpp3Dom( "versioning" );
versioning.addChild( addChildren( new Xpp3Dom( "versions" ), "version", allVersions ) );
addChild( versioning, "lastUpdated", timestamp );
metadata.addChild( versioning );
metadata = Xpp3DomUtils.mergeXpp3Dom( metadata, readMetadata( metadataFile ) );