public static BuildContext toBuildContext(
      JibContainerBuilder jibContainerBuilder, Containerizer containerizer)
      throws CacheDirectoryCreationException {
    return jibContainerBuilder.toBuildContext(containerizer);
  }
Test helper to expose package-private members of {@link JibContainerBuilder}.
jib-cli/src/test/java/com/google/cloud/tools/jib/api/JibContainerBuilderTestHelper.java