def METHOD_NAME(self, num):
    """helper function of _get_new_number, replace a number with another
    random number within the range of self.max_change."""
    if num not in [0, 2, 4]:
        change = int(num * self.max_change) + 1
        if num >= 0:
            num_list = np.random.randint(max(num - change, 1), num + change, self.n)
        else:
            num_list = np.random.randint(num - change, min(0, num + change), self.n)
        return num_list
    return []