def METHOD_NAME(self, x, knot, min_knot, max_knot):
    lambda_ = (max_knot - knot) / (max_knot - min_knot)
    return self.relu(x - knot) ** 3 - (lambda_ * self.relu(x - min_knot) ** 3 + (1 - lambda_) * self.relu(x - max_knot) ** 3)