configDesc.putListPropertyType("nodes", YamlNode.class);
constructor.addTypeDescription(configDesc);
// note that snakeyaml also throws nosuchmethod error when you use the
// non-deprecated
// constructor
Yaml yaml = new Yaml(new Loader(constructor));
Config config = (Config) yaml.load(source);
checkState(config != null, "missing config: class");
checkState(config.nodes != null, "missing nodes: collection");
Map<String, Node> backingMap = Maps.uniqueIndex(Iterables.transform(config.nodes, YamlNode.toNode),