@Override
  @NotNull
  public Collection<? extends PackagingSourceItem> getSourceItems(@NotNull ArtifactEditorContext editorContext,
                                                                  @NotNull Artifact artifact,
                                                                  @Nullable PackagingSourceItem parent) {
    if (parent == null) {
      if (!ArtifactElementType.getAvailableArtifacts(editorContext, artifact, true).isEmpty()) {
        return Collections.singletonList(new ArtifactsGroupSourceItem());
      }
    }
    else if (parent instanceof ArtifactsGroupSourceItem) {
      List<PackagingSourceItem> items = new ArrayList<>();
      for (Artifact another : ArtifactElementType.getAvailableArtifacts(editorContext, artifact, true)) {
        items.add(new ArtifactSourceItem(another));
      }
      return items;
    }
    return Collections.emptyList();
  }
@Override
  @NotNull
  public Collection<? extends PackagingSourceItem> getSourceItems(@NotNull ArtifactEditorContext editorContext,
                                                                  @NotNull Artifact artifact,
                                                                  @Nullable PackagingSourceItem parent)