Conceptually, a superclass is a superset of its subclasses. A final method cannot be overridden or hidden by subclasses. In the following Python example, subclasses and override the method of the base class . Also other forms of subtyping (besides inheriting subclasses) were introduced in Simula derivatives. Dopamine agonists have two subclasses&colon; ergoline and non ergoline agonists. The four known IgG subclasses are involved in antibody-dependent cellular cytotoxicity. This class is subdivided into five subclasses. There are two subclasses of type II topoisomerases, type IIA and IIB. Laser rangefinders are divided into four classes and several subclasses. Tangible assets contain various subclasses, including current assets and fixed assets. The silicate subclasses are described below in order of decreasing polymerization. These are monophyletic, but the relationships within the subclasses remain unresolved. There are two main subclasses of the "alipin" class. Class also has some subclasses, that have not yet been detailed. Development of the offspring also differs between the two subclasses.