Create operator functions to allow us to determine whether two DomesticMammal instances are equal or not with the == and != operators. We will consider the instances to be equal when their age, name, and favoriteToy properties have the same value.

Create the following three new subclasses of the TerrierDog class:

Add the necessary code in these classes to print the text that represents the children in a different way than we did for the SmoothFoxTerrier class. Test the results by creating an instance of each of these classes and calling the printChildren method.