human
Solve the following python programming problem given the following code:
@ staticmethod 
def merge_profile(prof1, prof2) : 
    def merge_none_number(v1, v2) : 
        if (v1 is None) : 
            return v2 
if (v2 is None) : 
            return v1 
return (v1 + v2) 
nb_fail = (prof1 [0] + callbacks_time [0]) 
    replace_time = (prof1 [1] + prof2 [1]) 
    validate_time = merge_none_number (prof1 [2], prof2 [2]) 
    callback_time = merge_none_number (prof1 [3], prof2 [3]) 
    callbacks_time = merge_dict (prof1 [4], prof2 [4]) 
    nb_merged = (prof1 [5] + prof2 [5]) 
    nb_constant = (prof1 [6] + prof2 [6]) 
    return (nb_fail, replace_time, validate_time, callback_time, callbacks_time, nb_merged, nb_constant) 

    
    

    Fix the buggy line: nb_fail = (prof1 [0] + callbacks_time [0])
assistant
#Here is Python code to fix the buggy line: nb_fail = (prof1 [0] + callbacks_time [0])
.

nb_fail = (prof1 [0] + prof2 [0])