assertNull(systemHelper.encodeUrlFilter(path));

        path = "abc";
        assertEquals(path, systemHelper.encodeUrlFilter(path));

        path = "あいう";
        assertEquals("%E3%81%82%E3%81%84%E3%81%86", systemHelper.encodeUrlFilter(path));

        path = "[]^$.*+?,{}|%\\";
        assertEquals(path, systemHelper.encodeUrlFilter(path));

        systemHelper.filterPathEncoding = null;

                "http://www.codelibs.org/");
        assertUrlLink("http://www.codelibs.org/あ", //
                "http://www.codelibs.org/あ");
        assertUrlLink("http://www.codelibs.org/%E3%81%82", //
                "http://www.codelibs.org/%E3%81%82");
        assertUrlLink("http://www.codelibs.org/%z", //
                "http://www.codelibs.org/%z");
        assertUrlLink("http://www.codelibs.org/?a=1&b=2", //