fails:Integer#gcdlcm returns [self, self] if self is equal to the argument
fails:Integer#gcdlcm returns an Array
fails:Integer#gcdlcm returns a two-element Array
fails:Integer#gcdlcm returns the greatest common divisor of self and argument as the first element
fails:Integer#gcdlcm returns the least common multiple of self and argument as the last element
fails:Integer#gcdlcm accepts a Bignum argument
fails:Integer#gcdlcm works if self is a Bignum
fails:Integer#gcdlcm raises an ArgumentError if not given an argument
fails:Integer#gcdlcm raises an ArgumentError if given more than one argument
fails:Integer#gcdlcm raises a TypeError unless the argument is an Integer
