@Test
    public void shouldWriteSampleForGremlinServer() throws IOException {
        final Graph g = TinkerGraph.open();
        IntStream.range(0, 10000).forEach(i -> g.addVertex("oid", i));
        DistributionGenerator.build(g)
                .label("knows")
                .seedGenerator(() -> 987654321L)
                .outDistribution(new PowerLawDistribution(2.1))
                .inDistribution(new PowerLawDistribution(2.1))
                .expectedNumEdges(100000).create().generate();

        final OutputStream os = new FileOutputStream(new File(tempPath, "sample.kryo"));
        GryoWriter.build().mapper(GryoMapper.build().version(GryoVersion.V3_0).create()).create().writeGraph(os, g);
        os.close();
    }
No assertions.  Just write out the graph for convenience.
tinkergraph-gremlin/src/test/java/org/apache/tinkerpop/gremlin/tinkergraph/structure/IoDataGenerationTest.java