docs: @NonNull
      public static List<String> unmodifiableNonNullListOfStrings(@Nullable List<?> args) {
          if (args == null || args.isEmpty()) {
              return emptyList();
          } else {
              final List<String> list = new ArrayList<String>(args.size());
  
              for (Object arg : args) {
                  list.add(arg != null ? arg.toString() : "null");
              }
  
              return unmodifiableList(list);
          }
      }