@Nonnull
    public List<AssemblyConfiguration> getAllAssemblyConfigurations() {
        final List<AssemblyConfiguration> assemblyConfigurations = getAssembliesConfiguration();

        if (assembly != null) {
            assemblyConfigurations.add(assembly);
        }

        return assemblyConfigurations;
    }
Use {@link #getAllAssemblyConfigurations()} unless you specifically want the configuration defined only by <code>assemblies</code>.
src/main/java/io/fabric8/maven/docker/config/BuildImageConfiguration.java