@NotNull
  public static Collection<? extends PsiElement> asList(@Nullable PsiElement elem) {
    if (elem == null) return new ArrayList<>();
    if (elem instanceof GrListOrMap) {
      return Arrays.asList(((GrListOrMap)elem).getInitializers());
    } else if (elem instanceof GrAnnotationArrayInitializer){
      return Arrays.asList(((GrAnnotationArrayInitializer)elem).getInitializers());
    } else {
      return Collections.singleton(elem);
    }
  }
@NotNull
  public static Collection<? extends PsiElement> asList(@Nullable PsiElement elem)