def METHOD_NAME(theta):
    valid_theta_types = (list, int, float, tuple)
    if not isinstance(theta, valid_theta_types):
        raise ValueError(f"invalid input, please use one of {valid_theta_types}")
    if isinstance(theta, (int, float)):
        theta = [theta]
    if isinstance(theta, tuple):
        theta = list(theta)
    return theta