Visual basic invoice class application

Create a class called Invoice that a 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 variables—(private)

• a part number (type String),
• a part description (type String),
• a quantity of the item being purchased (type int ) -in case of negative value set this to zero 
• price per item (double) -in case of negative value set this to zero

Constructor
Your class  should have a constructor(with 3 parameter) that initializes the four instance variables. 

Methods

1. Provide a set and a get method for each instance variable.
2. In addition, provide a method named getInvoiceAmount 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
3. InvoiceTest that demonstrates class Invoice’s capabilities. provide a method getInvoiceDetail that returns all the information(in the form  of string) contained in    the invoice object