public AssemblyFiles getAssemblyFiles(MavenSession session, String assemblyName) {
        if (archivers.containsKey(assemblyName)) {
            return archivers.get(assemblyName).getAssemblyFiles(session);
        }
        return null;
    }
Contains several {@link MappingTrackArchiver} instances, one per assembly
src/main/java/io/fabric8/maven/docker/assembly/TrackArchiverCollection.java