public void test() {
        MultiGroupConversionRule cr2 = new MultiGroupConversionRule(Pattern.compile("(.*)(Log)"));
        cr2.addReplacement(2, "LOGGER");

        String s = "abcd Log";
        Pattern pat = cr2.getPattern();
        Matcher m = pat.matcher(s);

        assertTrue(m.matches());
        String r = cr2.replace(m);
        assertEquals("abcd LOGGER", r);

        System.out.println(r);
    }
In this test we see that we can use more simple Pattern to do the
conversion
slf4j-migrator/src/test/java/org/slf4j/migrator/AternativeApproach.java