Energy drink Energy drink An energy drink is a type of drink containing sugar and stimulant compounds, usually caffeine, which is marketed as providing mental and physical stimulation (marketed as "energy", but distinct from food energy). They may or may not be carbonated and may also contain other sweeteners, herbal extracts, taurine, and amino acids. They are a subset of the larger group of energy products, which includes bars and gels, and distinct from sports drinks, which are advertised to enhance sports performance. There are many brands and varieties in this drink category. Coffee, tea and other naturally caffeinated drinks are usually
Is-a and type(type(a)) is a metatype. While as distributed all types have the same metatype (PyType_Type, which is also its own metatype), this is not a requirement. The type of classic classes, known as types.ClassType, can also be considered a distinct metatype. In Java, is-a relation between the type parameters of one class or interface and the type parameters of another are determined by the extends and implements clauses. Using the Collections classes, ArrayList<E> implements List<E>, and List<E> extends Collection<E>. So ArrayList<String> is a subtype of List<String>, which is a subtype of Collection<String>. The subtyping relationship is preserved between the types