public Grok cachedGrokForPattern(String pattern) {
        return cachedGrokForPattern(pattern, false);
    }
@Test
    public void cachedGrokForPattern() {
        final Grok grok = grokPatternRegistry.cachedGrokForPattern("%{TESTNUM}");
        assertThat(grok.getPatterns()).containsEntry(GROK_PATTERN.name(), GROK_PATTERN.pattern());
    }