assertFalse(CharUtil.isUrlChar('`')); // backtick (just before 'a')
        assertFalse(CharUtil.isUrlChar('{')); // left brace (just after 'z')
        assertFalse(CharUtil.isUrlChar('^')); // caret (before 'a' range)
        assertFalse(CharUtil.isUrlChar('|')); // pipe (not in valid set)
    }