@CheckForNull
  public User getSubmitter() {
    return submitter;
  }
@Test
  public void empty_in_submitterLogin_is_considered_as_null() {
    CeTask ceTask = underTest.setUuid("uuid").setType("type")
      .setSubmitter(new CeTask.User("USER_ID", ""))
      .build();

    assertThat(ceTask.getSubmitter().login()).isNull();
  }