@Test
    @LoadGraphWith(MODERN)
    public void shouldNotAllowEmptyMemoryKeys() throws Exception {
        try {
            graphProvider.getGraphComputer(graph).program(new VertexProgramD()).submit().get();
            fail("Providing empty memory key should fail");
        } catch (Exception ex) {
            validateException(Memory.Exceptions.memoryKeyCanNotBeEmpty(), ex);
        }
    }
@author Marko A. Rodriguez (http://markorodriguez.com)
gremlin-test/src/main/java/org/apache/tinkerpop/gremlin/process/computer/GraphComputerTest.java