public static Graph open(final Configuration conf) {
            if (conf.containsKey("throw")) throw new RuntimeException("you said to throw me");
            return new MockGraphWithFactory(conf);
        }
@author Stephen Mallette (http://stephen.genoprime.com)
gremlin-core/src/test/java/org/apache/tinkerpop/gremlin/structure/util/GraphFactoryTest.java