human
Solve the following python programming problem given the following code:
def test_sum_3() : 
    def fun(x) : 
        return to_scalar (np.sum (x, axis = 0, keepdims = True)) 
d_fun = (lambda x : to_scalar (grad (fun) (x))) 
    mat = npr.randn (10, 11) 
    check_grads (fun, d_fun) 
    check_grads (d_fun, mat) 

    
    

    Fix the buggy line: check_grads (fun, d_fun)
assistant
#Here is Python program to fix the buggy line: check_grads (fun, d_fun)
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check_grads (fun, mat)