A programmer wants to modify the CheckDigit class to keep track of how many times a call to isValid is made with an incorrect check digit. Any time a call to isValid is made with an incorrect check digit, the count should be increased by one. The programmer would like to implement this change without making any changes to the signature of the isValid method or overloading isValid. Write a description of how you would change the CheckDigit class in order to support this modification. Do not write the program code for this change. Make sure to include the following in your response.1. Identify any new or modified variables , constants, or methods.2. Describe, for each new or revised variable, constant, or method, how it would change or be implemented, including visibility and type.