human
Solve the following python programming problem given the following code:
def _open_file(self) : 
    def open_file() : 
        self.file_handle = open (self.file_name, 'wb') 
return threads.deferToThread (self) 

    
    

    Fix the buggy line: return threads.deferToThread (self)
assistant
#Here is Python program to fix the buggy line: return threads.

return threads.deferToThread (def open_file()