<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def iter_tree_with_handed_function(self, function, *function_args):
 """Iterate tree view with condition check function"""

        def iter_all_children(row_iter, function, function_args):
            if isinstance(row_iter, Gtk.TreeIter):
                function(row_iter, *function_args)
                for n in reversed(range(self.tree_store.iter_n_children(row_iter))):
                    child_iter = self.tree_store.iter_nth_child(row_iter, n)
                    iter_all_children(child_iter, function, function_args)
            else:
                self._logger.warning("Iter has to be TreeIter -> handed argument is: {0}".format(row_iter))

        # iter on root level of tree
        next_iter = self.tree_store.get_iter_first()
        while next_iter:
            iter_all_children(next_iter, function, function_args)
            next_iter = self.tree_store.iter_next(next_iter)