@Test(expected = IllegalArgumentException.class)
    public void shouldThrowExceptionForNoSettings() {
        new ConfigurationGroovyCustomizer();
    }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-groovy/src/test/java/org/apache/tinkerpop/gremlin/groovy/jsr223/ConfigurationCustomizerProviderTest.java