II$.$ Design a class Cube, that has the following properties:

A base as a Rectangle object and a height. So your class has two private members: Rectangle base and double height.

A default constructor tht sets the base to default Rectangle and height to $0$

A Constructor that accepts a Rectangle and a double

A constructor that accepts three doubles

Getters$/$setters $($also getters$/$setters for length and width$)$

Method Area$(),$ that computes the areas of all surfaces of the cube; use any already defines method previously in Rectangle class.

Method Volume$()$ that computes the volume, use any already defines method previously in Rectangle class.

Method add that accepts a Cube and returns the sum of this and the input Cube, without changing this object

toString$()$ that returns the object as a string

equals$()$ that accepts a Cube and returns true if the two are the same. Use previously defined methods in this class or in the Rectangle class whenever possible.