'pathrender: pattern parsing'

def test_parsing(self):

    pattern = Pattern(u'{$Disc.}$Track    -    $Artist    -    $Title{    [$Year]}')
    expected = [_pr._OptionalBlock([_pr._Replacement(u'$Disc'), _pr._LiteralText(u'.')]), _pr._Replacement(u'$Track'), _pr._LiteralText(u'    -    '), _pr._Replacement(u'$Artist'), _pr._LiteralText(u'    -    '), _pr._Replacement(u'$Title'), _pr._OptionalBlock([_pr._LiteralText(u'    ['), _pr._Replacement(u'$Year'), _pr._LiteralText(u']')])]
    self.assertEqual(expected, pattern._pattern)
    self.assertItemsEqual([], pattern.warnings)
