public static Property GetDiscriminator(this ClassInfo clazz) => clazz.GetChildProperty <Property>("discriminator");
 public static IList <Collection> GetBags(this ClassInfo clazz) => clazz.GetChildProperties <Collection>("bag");
 public static IdProperty GetIdProperty(this ClassInfo clazz) => clazz.GetChildProperty <IdProperty>("id");
 public static IList <Collection> GetSets(this ClassInfo clazz) => clazz.GetChildProperties <Collection>("set");
 public static IList <Property> GetOneToOneProperties(this ClassInfo clazz) => clazz.GetChildProperties <Property>("one-to-one");
 public static IList <Property> GetProperties(this ClassInfo clazz) => clazz.GetChildProperties <Property>("property");
 public static CompositeId GetCompositeId(this ClassInfo clazz) => clazz.GetChildProperty <CompositeId>("composite-id");
 public static Property GetKeyProperty(this ClassInfo clazz) => clazz.GetChildProperty <Property>("key");