a$.$ Main Class: $($ at least have $3$ attributes $)$

Create a class named Vehicle to represent the common features shared by all vehicles. This class should include attributes like brand, model, and year of manufacture.

Also, define a method named describe$()$ to provide a description of the vehicle.

b$.$ Subclass: $($Must extend Main class and at least have $3$ extra attributes $)$

Develop a subclass called Car, which inherits from the Vehicle class. In addition to the common attributes, the Car class should have an extra attribute to store its mileage.

Implement a method named calculate$\_$mileage$()$ to return the car's mileage.

c$.$ Provide an example illustrating how to create a Car object and utilize its methods.

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