code: protected Class<?> getValueType(AnnotatedElement element) {
          if (element instanceof Field) {
              return ((Field) element).getType();
          }
          if (element instanceof Method) {
              return ((Method) element).getReturnType();
          }
          throw new PropertyLoaderException("Could not get element type");
      }
docs: Returns the type of the value for given element. {@link Field} and {@link Method}
  are only supported.