human
Solve the following python programming problem given the following code:
def add_son_manipulator(self, manipulator) : 
    'Add a new son manipulator to this database.

        **DEPRECATED** - `add_son_manipulator` is deprecated.

        .. versionchanged:: 3.0
          Deprecated add_son_manipulator.
        ' 
    warnings.warn ('add_son_manipulator is deprecated', DeprecationWarning, stacklevel = 2) 
    base = SONManipulator () 
    def method_overwritten(instance, method) : 
        'Test if this method has been overridden.' 
        return (getattr (instance, method).__func__ != getattr (base, method).__func__) 
if manipulator.will_copy () : 
        if method_overwritten (manipulator, 'transform_incoming') : 
            self.__incoming_copying_manipulators.insert (0, manipulator) 
if method_overwritten (manipulator, 'transform_outgoing') : 
            self.__outgoing_copying_manipulators.insert (0, manipulator) 
else : 
        if method_overwritten (manipulator, 'transform_incoming') : 
            self.__incoming_manipulators.insert (0, base) 
if method_overwritten (manipulator, 'transform_outgoing') : 
            self.__outgoing_manipulators.insert (0, manipulator) 

    
    

    Fix the buggy line: self.__incoming_manipulators.insert (0, base)
assistant
#Here is Python code to fix the buggy line: self.

self.__incoming_manipulators.insert (0, manipulator)