generate irt model

def generate_irt(
        n_students: int,
        n_questions: int,
        a: float = 1,
        b: float = 1,
        c: float = 0.5,
        a_values: np.ndarray = None,
        b_values: np.ndarray = None,
        c_values: np.ndarray = None,
        seed: int = 1
) -> (np.ndarray, np.ndarray, np.ndarray, np.ndarray):
    np.random.seed(seed)

    if a_values is None:
        a_values = np.random.uniform(low=0, high=a, size=n_questions)
    else:
        assert a_values.shape == (n_questions,)

    if b_values is None:
        b_values = np.random.uniform(low=0, high=b, size=n_questions)
    else:
        assert b_values.shape == (n_questions,)

    if c_values is None