How to use the mathy.agent.training.problems.rand_int function in mathy

def two_variable_terms_separated_by_constant():
    variable = rand_var()
    problem = "{}{} + {} + {}{}".format(
        rand_int(), variable, const, rand_int(), variable
    )
    return problem, 3

def two_variable_terms_separated_by_constant():
    variable = rand_var()
    problem = "{}{} + {} + {}{}".format(
        rand_int(), variable, const, rand_int(), variable
    )
    return problem, 3

def two_variable_terms():
    variable = rand_var()
    problem = "{}{} + {}{}".format(rand_int(), variable, rand_int(), variable)
    return problem, 2

def two_variable_terms():
    variable = rand_var()
    problem = "{}{} + {}{}".format(rand_int(), variable, rand_int(), variable)
    return problem, 2