/**
  * Creates a copy from a different {@link JsonStringDocument}, but changes the CAS value.
  *
  * @param doc the original {@link JsonStringDocument} to copy.
  * @param cas the CAS (compare and swap) value for optimistic concurrency.
  * @return a copied {@link JsonStringDocument} with the changed properties.
  */
 public static JsonStringDocument from(JsonStringDocument doc, long cas) {
   return JsonStringDocument.create(
       doc.id(), doc.expiry(), doc.content(), cas, doc.mutationToken());
 }
 /**
  * Creates a copy from a different {@link JsonStringDocument}, but changes the document ID and
  * content.
  *
  * @param doc the original {@link JsonStringDocument} to copy.
  * @param id the per-bucket unique document id.
  * @param content the content of the document.
  * @return a copied {@link JsonStringDocument} with the changed properties.
  */
 public static JsonStringDocument from(JsonStringDocument doc, String id, String content) {
   return JsonStringDocument.create(id, doc.expiry(), content, doc.cas(), doc.mutationToken());
 }