if (length == elements.length) {
        dedupAndCoalesce(true);
      } else if (forceCopyElements) {
        this.elements = Arrays.copyOf(elements, elements.length);
        // we don't currently need to copy the counts array, because we don't use it directly
        // in built ISMs
      }
      forceCopyElements = false;
    }

    private void dedupAndCoalesce(boolean maybeExpand) {
      if (length == 0) {