human
Solve the following python programming problem given the following code:
def make_fast_mul_f(library) : 
    NID_secp256k1_GROUP = library.EC_GROUP_new_by_curve_name (714) 
    def fast_mul(point, N) : 
        bn_x = library.BignumType (point.x ()) 
        bn_y = library.BignumType (point.y ()) 
        bn_n = library.BignumType (N) 
        ctx = library.BN_CTX_new () 
        ec_result = library.EC_POINT_new (NID_secp256k1_GROUP) 
        ec_point = library.EC_POINT_new (NID_secp256k1_GROUP) 
        library.EC_POINT_set_affine_coordinates_GFp (NID_secp256k1_GROUP, ec_point, bn_x, bn_y, ctx) 
        library.EC_POINT_mul (NID_secp256k1_GROUP, ec_result, None, ec_point, bn_n, ctx) 
        library.EC_POINT_get_affine_coordinates_GFp (NID_secp256k1_GROUP, ec_result, bn_x, bn_y, ctx) 
        library.EC_POINT_free (ec_point) 
        library.EC_POINT_free (ec_result) 
        library.BN_CTX_free (ctx) 
        return type (point) (point.curve (), bn_x.to_int (), bn_y.to_int ()) 
return library 

    
    

    Fix the buggy line: return library
assistant
#Here is Python code to fix the buggy line: return library
.

return def fast_mul(