code: @SuppressWarnings("unchecked")
    public static Class<?> getValueType(Class<? extends CoreAnnotation> key) {
      Class type = valueCache.get(key);
      if (type == null) {
        try {
          type = key.newInstance().getType();
        } catch (Exception e) {
          throw new RuntimeException("Unexpected failure to instantiate - is your key class fancy?", e);
        }
        valueCache.put((Class)key, type);
      }
      return type;
    }
docs: Returns the runtime value type associated with the given key.  Caches
  results.