Create a Tip Calculator with two classes: TipCalculator (the JavaFX class) and Order

• Start with an Order class with two instance variables, item a String and price a double; include two constructors, a no-parameter constructor that passes default values empty String and zero (0) to the second constructor which then calls the set methods for item and price; the set method for price validates that price is greater than zero (0); include get methods for both instance variables; there is no need for a toString() method
• Instantiate ten objects from the Order class in the start() method of the JavaFX application from which two ObservableList objects should be instantiated: (a) an ObservableList of Strings populated from the get method for the item field; and (b) an ObservableList of Doubles (use the wrapper class as the sub type to instantiate) populated from the get method for the price field
• The JavaFX form will consist of (a) a ListView of Strings from the ObservableList of items; (b) a Slider that represents tip percentage as an int between 15% and 25% (show the current value of the tip percent slider in a matching Label); (c) a Button that is clicked to calculate the total bill; and (d) a result Label
• Include an event handler method for the Button that calculates the total bill as follows: the price field from the ObservableList that matches the selected item from the ListView (the user may purchase only one item at a time) times sales tax (8.625%) plus the tip which is the matching price from the ObservableList times the percentage from the Slider; display with text labels in the result Label the selected item, its matching price, the sales tax, the amount of the tip and the total bill