Write a full class definition for a class named Accumulator, and containing the following members: – A data member named sum of type integer. – A constructor that accepts no parameters. The constructor initializes the data member sum to 0. – A member function named getSum that accepts no parameters and returns an integer. getSum returns the value of sum. – A member function named add that accepts an integer parameter and returns no value. add increases the value of sum by the value of the parameter.