imageDesc.putListPropertyType("images", String.class);
constructor.addTypeDescription(imageDesc);
// Issue 855: testng is rev-locking us to snakeyaml 1.6
// we have to use old constructor until this is fixed
Yaml yaml = new Yaml(new Loader(constructor));
Config config = (Config) yaml.load(yamlDescriptor);
checkState(config != null, "missing config: class");
checkState(config.images != null, "missing images: collection");
Map<Image, YamlImage> backingMap = Maps.newLinkedHashMap();