code: public <T extends ICalProperty> List<T> getProperties(Class<T> clazz) {
  		return new ICalPropertyList<T>(clazz);
  	}
docs: Gets all properties of a given class. Changes to the returned list will
  update the {@link ICalComponent} object, and vice versa.
  @param clazz the property class
  @param <T> the property class
  @return the properties