human
I wrote the below code

    def _check_args(a1, a2, theta):
        condth = (theta > 0)
        conda1 = ((a1 > 0) and (a1 <= 1))
        conda2 = ((a2 > 0) and (a2 <= 1))
        return (condth and conda1 and conda2)
    if (not np.all(_check_args(a1, a2, theta))):
        raise ValueError('invalid    args')
    transf = (1 - ((((a1 * (1 - t)) ** ((-1.0) / theta)) + ((a2 * t) ** ((-1.0) / theta))) ** (- theta)))
    return transf

What's a good function header?
 ... Here's a good function header?
assistant
#Here's a good function header.

def transform_joe(t, a1, a2, theta):