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.