Write a class named ParkingMeter containing:
An instance variable named timeLeft of type int , initialized to 0.
A method named add that accepts an integer parameter . If the value of the parameter is equal to 25, the value of timeLeft is increased by 30; otherwise no increase is performed. add returns a boolean value : true if timeLeft was increased , false otherwise.
A method named tick that accepts no parameters and returns no value . tick decreases the value of timeLeft by 1, but only if the value of timeLeft is greater than 0.
A method named isExpired that accepts no parameters . isExpired returns a boolean value : true if the value of timeLeft is equal to 0; false otherwise.