code: @NullSafe
    public static <T> List<T> nullSafeList(List<T> list) {
      return list != null ? list : Collections.emptyList();
    }
docs: Null-safe method returning the given {@link List} or an empty {@link List} if null.
  
  @param <T> Class type of the elements in the {@link List}.
  @param list {@link List} to evaluate.
  @return the given {@link List} or an empty {@link List} if null.
  @see java.util.Collections#emptyList()
  @see java.util.List