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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def start_editing(self, treeview, event):
 """Make the treeview grab the focus and start editing the cell that the user has clicked to avoid confusion with two or three clicks before editing a keybinding. Thanks to gnome-keybinding-properties.c =) """

        x, y = int(event.x), int(event.y)
        ret = treeview.get_path_at_pos(x, y)
        if not ret:
            return False

        path, column, cellx, celly = ret

        treeview.row_activated(path, Gtk.TreeViewColumn(None))
        treeview.set_cursor(path)

        return False