String value;

        value = transformer.normalizeCanonicalUrl("http://hoge.com/", "a");
        assertEquals("http://hoge.com/a", value);

        value = transformer.normalizeCanonicalUrl("http://hoge.com/", "aaa");
        assertEquals("http://hoge.com/aaa", value);

        value = transformer.normalizeCanonicalUrl("http://hoge.com/", "/aaa");
        assertEquals("http://hoge.com/aaa", value);

        if (StringUtil.isBlank(canonicalUrl)) {
            return null;
        }
        return normalizeCanonicalUrl(responseData.getUrl(), canonicalUrl);
    }

    protected String normalizeCanonicalUrl(final String baseUrl, final String canonicalUrl) {
        try {
            final URL u = new URL(baseUrl);