19.1 Polymorphism
19.2 Inclusion Polymorphism (Inheritance and Subtyping)
19.2.1 private Visibility and Inheritance
19.2.2 Protected Visibility
19.2.3 Calling Methods on the Supertype
19.2.4 Anonymous Classes
19.2.5 Abstract Classes
19.2.6 traits
19.2.7 final
19.2.8 Method Resolution
19.2.9 Inheriting from Function Types
19.3 Inheritance in the Project
19.3.1 Drawables
19.3.2 Integration with Drawing
19.4 Parametric Polymorphism
19.4.1 Parametric Types
19.4.2 Parametric Functions and Methods
19.4.3 Type Bounds