Define a class named multiitemsale that represents a sale of multiple items of type sale given in display 8.1 (or of the types of any of its descendent classes). the class multiitemsale will have an instance variable whose type is sale[], which will be used as a partially filled array. there will also be another instance variable of type int that keeps track of how much of this array is currently used. the exact details on methods and other instance variables, if any, are up to you. use this class in a program that obtains information for items of type sale and of type discountsale (display 8.2) and that computes the total bill for the list of items sold. savitch, walter. absolute java (p. 520). pearson education. kindle edition.