insert
Creates a new row at @position. @iter will be changed to point to this new row. If @position is -1 or is larger than the number of rows on the list, then the new row will be appended to the list. The row will be empty after this function is called. To fill in values, you need to call gtk_list_store_set() or gtk_list_store_set_value().
Parameters
iter
An unset GtkTreeIter
to set to the new row
position
position to insert the new row, or -1 for last