//create a session
final SessionRequestMessage outMsg = new SessionRequestMessage();
outMsg.setRequestAsUUID(UUID.randomUUID());
outMsg.metaSetGraphName("undefined");
RexProMessage inMsg = client.execute(outMsg);
Assert.assertNotNull(inMsg.Session);
Assert.assertTrue(inMsg instanceof ErrorResponseMessage);
Assert.assertEquals(((ErrorResponseMessage) inMsg).metaGetFlag(), ErrorResponseMessage.GRAPH_CONFIG_ERROR);
}