@Test
public void testStoreUser() {

    Resource newUserId = VALUE_FACTORY.createIRI("http://mobi.com/users/newuser");
    User newUser = userFactory.createNew(newUserId);
    newUser.setUsername(VALUE_FACTORY.createLiteral("newuser"));
    engine.storeUser(newUser);
    RepositoryConnection connection = repo.getConnection();
    RepositoryResult<Statement> statements = connection.getStatements(newUserId, null, null);
    assertTrue(statements.hasNext());
    connection.close();
}