the first question is the prerequisite for the second question

thank You

Tractors Pretend we work for a company that leases tractors. Let us create a class for tractors that might be used as part of a fleet management system. All of your classes should be in separate files within your project package. Name your package testtractor Create a class named Tractor. It will have instance variables for the Vehicle ID, Rental Rate, Rental Days. Be sure to make them all private. It will have an method for calculating RentalProfit). Which will be rental days times rental rate. Create getter and setter methods for the Tractor's instance variables. Make sure the setter perform reasonable validation Create a zero parameter constructor and a fully parameterized constructor for the class. Override the toString() method to return the dass name, VIN, Rental Days and Rental Rate in a well formatted string Create an application class named testTractor java to test drive the tractor class. In your test driver's main() method create a Tractor object using the zero parameter constructor. Use the setters to assign values to the tractor. Use the toString() to display information about the Tractor. Also create a Tractor using the parameterized constructor. Use its getter methods to display information about the Tractor Create a third tractor. Use the methods and try to set invalid values. Display the results. Nullify the third tractor object. Submit your testTractor.java file and Tractor.java file. + . . . . Tractors Modification of the Tractor project. Make a copy of your testTractor Package name it testLoader and make the following modifications and additions Let us create a class hierarchy for tractors to use in a fleet management system. All of your classes should be in separate files within your project package. Name your package testloader. Modify the base class named Tractor. The Tractor class will have a static attribute called Company. All tractors are owned by the same company Create a class named Loader that inherits from Tractor. Loaders had a Bucket Sire (1-5) the Bucket Size effects the RentalProfit by an additional $100-$500. You will need to Override the RentalProfit method to perform this calculation correctly. Create a fully parameterized constructor that uses a reference to super). Override the toString to contain the base tractor information plus the Bucket Size option Create a class called Harvester. Harvesters are must be rented for at least 20 days. Override the setter for Rental days to reflect this. Harvesters may have a tow behind trailer option (1-3) that adds $1000-$3000 to the RentalProfit() calculation. Create a fully parameterized constructor that uses a reference to super(). Override the toString to contain the base tractor Information plus the trailer option In your test drivers main() method create a Tractor, Loader and a Harvester. Using the zero parameter contructor. Then use the set methods to set all attributes. Also create a Tractor, Loader and Harvester using the parameterized contructor Set the company name to your name. Use the toString methods to display the information for each tractor. Be sure to display the rentalPronto calculation in your test driver. Create a zip file for your package and submit it for grading