Write a class encapsulating the concept of a rational number, assuming a rational number has the following attributes: an integer representing the numerator of the rational number another integer representing the denominator of the rational number Include a constructor, the accessors and mutators, and methods toString and equals. You should not allow the denominator to equal to 0; you should give it the default value 1 in case the corresponding argument of the constructor or a method is 0. Also include methods performing multiplication of a rational number by another and addition of a rational number to another, returning the resulting rational number in both cases. Write a client class to test all the methods in your class.