def METHOD_NAME(self):
    eq = self.assertEqual
    zz = self.zz
    text = zz.text
    eq(self.zz.ztext, '# ignore #')
    # Prepend text.
    text.tag_add('sel', '2.0', '5.end')
    zz.z_in_event()
    text.undo_block_start.reset_mock()
    text.undo_block_stop.reset_mock()
    # Select a few lines to remove text.
    text.tag_remove('sel', '1.0', 'end')
    text.tag_add('sel', '3.0', '4.end')
    eq(zz.z_out_event(), 'break')
    expected = [False, True, False, False, True, False, False]
    actual = self.checklines(text, zz.ztext)
    eq(expected, actual)
    text.undo_block_start.assert_called_once()
    text.undo_block_stop.assert_called_once()