/**
  * Generates a collection meta token representing this collection.
  *
  * @return String.
  */
 public String buildCollectionMetaToken() {
   Map<String, Object> claims = data.asMap();
   boolean isNetworkIssued = isNetworkIssued();
   claims.put("iss", isNetworkIssued ? site.getNetwork().getUrn() : site.getUrn());
   return LivefyreUtil.serializeAndSign(
       claims, isNetworkIssued ? site.getNetwork().getData().getKey() : site.getData().getKey());
 }