Kansas Hardware management approaches you that they want to computerize their invoice system from the current manual system to a digital one. Using your knowledge of Object Oriented Programing, create a class called Invoice that Kansas hardware store might use to represent an invoice for an item sold at the store. An Invoice should include four pieces of information as instance variablesa part number(type String),a part description(type String),a quantity of the item being purchased (type int) and a price per item (double). Your class should have a constructor that initializes the four instance variables. Provide a set and a get method for each instance variable. In addition, provide a method named getInvoice Amount that calculates the invoice amount (i.e., multiplies the quantity by the price per item), then returns the amount as a double value. If the quantity is not positive, it should be set to 0. If the price per item is not positive, it should be set to 0.0. Write a test application named InvoiceTest that demonstrates class Invoices capabilities.