Give the definition of two classes, Patient and Billing, whose objects are records for a c...

Give the definition of two classes, Patient and Billing, whose objects are records for a clinic. Patient will be derived from the class Person given in Programming Project 4. A Patient record has the patient's name (inherited from the class Person) and primary physician, of type Doctor defined in Programming Project 4. A Bi1ing object will contain a Patient object, a Doctor object, and an amount due of type double. Be sure your classes have a reasonable complement of constructors, accessor, and mutator member functions, an overloaded assignment operator, and a copy constructor. First write a driver program to test all your member functions, and then write a test program that creates at least two patients, at least two doctors, and at least two Bi11ing records, then prints out the total income from the Billing records.