human
Solve the following python programming problem given the following code:
def _add_get_or_change_to_method(self) : 
    '
        Add a ``get_or_change_to_x()`` method to the element class for this
        child element.
        ' 
    def get_or_change_to_child(obj) : 
        child = getattr (obj, self._prop_name) 
        if (child is not None) : 
            return child 
remove_group_method = getattr (obj, self._remove_group_method_name) 
        remove_group_method () 
        add_method = getattr (obj, self._add_method_name) 
        child = add_method () 
        return child 
get_or_change_to_child.__doc__ = ('Return the ``<%s>`` child, replacing any other group element if found.' % self._nsptagname) 
    self._add_to_class (self._get_or_change_to_method_name, self) 

    
    

    Fix the buggy line: self._add_to_class (self._get_or_change_to_method_name, self)
assistant
#Here is Python code to fix the buggy line: self.

self._add_to_class (self._get_or_change_to_method_name, get_or_change_to_child)