@Override
  public void register(String qpKey, Status status) {
    checkNotNull(qpKey, "qpKey can't be null");
    checkNotNull(status, "status can't be null");
    checkState(statuses.put(qpKey, status) == null, "Quality Profile '%s' is already registered", qpKey);
  }
@Test
  public void register_fails_with_NPE_if_status_is_null() {
    assertThatThrownBy(() -> underTest.register("key", null))
      .isInstanceOf(NullPointerException.class)
      .hasMessage("status can't be null");
  }