### Question:
NoopIndexNameFormatter implements IndexNameFormatter<LogEvent> { @PluginBuilderFactory public static NoopIndexNameFormatter.Builder newBuilder() { return new NoopIndexNameFormatter.Builder(); } protected  NoopIndexNameFormatter(String indexName); @Override String format(LogEvent logEvent); @PluginBuilderFactory static NoopIndexNameFormatter.Builder newBuilder();  }### Answer:
@Test public void builderThrowsWhenNameIsNull() { NoopIndexNameFormatter.Builder builder = NoopIndexNameFormatter.newBuilder(); expectedException.expect(ConfigurationException.class); expectedException.expectMessage("indexName"); builder.build(); }