def credits(self):
        """Returns either a tuple representing the credit range or a
        single integer if the range is set to one value.

        Use self.cred to always get the tuple.
        """
        if self.cred[0] == self.cred[1]:
            return self.cred[0]
        return self.cred
Returns either a tuple representing the credit range or a
        single integer if the range is set to one value.

        Use self.cred to always get the tuple.