human
Solve the following python programming problem given the following code:
def check_reference(self, x) : 
    def func() : 
        return (x,) 
(gx,) = gradient_check.numerical_grad (func, (self,), (1,)) 
    gradient_check.assert_allclose (cuda.to_cpu (gx), 1) 

    
    

    Fix the buggy line: (gx,) = gradient_check.numerical_grad (func, (self,), (1,))
assistant
#Here is Python program to fix the buggy line: (gx,) = gradient_check.

(gx,) = gradient_check.numerical_grad (func, (x,), (1,))