Write the implementation (.cpp file) of the Accumulator class of the previous exercise. The full specification of the class is: An data member named sum of type integer. A constructor that accepts no parameters. The constructor initializes the data member sum to 0. A function named getSum that accepts no parameters and returns an integer. getSum returns the value of sum. A function named add that accepts an integer parameter and returns no value. add increases the value of sum by the value of the parameter.