human
Solve the following python programming problem given the following code:
def test_4dyear(self) : 
    if (self._format == '%04d') : 
        self.test_year ('%04d') 
else : 
        def year4d(y) : 
            return time.strftime ('%4Y', ((y,) + ((0,) * 8))) 
self.test_year ('%04d', func = self) 

    
    

    Fix the buggy line: self.test_year ('%04d', func = self)
assistant
#Here is Python program to fix the buggy line: self.

self.test_year ('%04d', func = def year4d()