docs: @Nonnull
      public List<FilePath> list(final FileFilter filter) throws IOException, InterruptedException {
          if (filter != null && !(filter instanceof Serializable)) {
              throw new IllegalArgumentException("Non-serializable filter of " + filter.getClass());
          }
          return act(new ListFilter(filter), (filter != null ? filter : this).getClass().getClassLoader());
      }