human
Solve the following python programming problem given the following code:
def _write_Collection(self, out) : 
    code = '
        def __len__(self):
            return self._vtk_obj.GetNumberOfItems()

        def __iter__(self):
            self._vtk_obj.InitTraversal()
            return self

        def next(self):
            try:
                val = self._vtk_obj.GetNextItem()
            except AttributeError:
                val = self._vtk_obj.GetNextProp()
            if val is None:
                raise StopIteration
            return wrap_vtk(val)

        __next__ = next

        def __getitem__(self, key):
            obj = self._vtk_obj
            if type(key) != type(1):
                raise TypeError("Only integers are valid keys.")
            ni = obj.GetNumberOfItems()
            if key < 0:
                key =  ni + key
            ret = obj.GetItemAsObject(key)
            if ret is None:
                raise IndexError("Index %s out of range."%key)
            return wrap_vtk(ret)

        def __setitem__(self, key, val):
            obj = self._vtk_obj
            if type(key) != type(1):
                raise TypeError("Only integers are valid keys.")
            ni = obj.GetNumberOfItems()
            if key < 0:
                key =  ni + key
            if key < 0 or key >= ni:
                raise IndexError("Index out of range.")
            obj.ReplaceItem(key, deref_vtk(val))

        def __delitem__(self, key):
            obj = self._vtk_obj
            if type(key) != type(1):
                raise TypeError("Only integers are valid keys.")
            ni = obj.GetNumberOfItems()
            if key < 0:
                key =  ni + key
            if key < 0 or key >= ni:
                raise IndexError("Index %s out of range."%key)
            obj.RemoveItem(key)

        def __repr__(self):
            return repr([repr(x) for x in self])

        def append(self, val):
            self._vtk_obj.AddItem(deref_vtk(val))

        def extend(self, arr):
            obj = self._vtk_obj
            for i in arr:
               ...

    
    

    Fix the buggy line: out.write (self.indent.format (out))
assistant
#Here is Python code to fix the buggy line: out.

out.write (self.indent.format (code))