'motions: lowercase mode is alpha, digit and _, uppercase is delim by spaces
b/B: backward short/long word'

def test_motion_backward(self):

    r = ViModeTest()
    r._set_line('abc_123        def--456.789        x')
    r.input('Escape')
    r.input('"$"')
    self.assertEqual(23, r.line_cursor)
    r.input('"b"')
    self.assertEqual(18, r.line_cursor)
    r.input('"b"')
    self.assertEqual(17, r.line_cursor)
    r.input('"B"')
    self.assertEqual(9, r.line_cursor)
    r.input('"B"')
    self.assertEqual(0, r.line_cursor)
