@Override
  public Set<String> codeVariants() {
    if (codeVariants == null) {
      return Set.of();
    } else {
      return ImmutableSet.copyOf(codeVariants);
    }
  }
@Test
  void codeVariants_whenNull_shouldReturnEmptySet() {
    assertThat(issue.codeVariants()).isEmpty();
  }