code: private void marshalCreatedAndUpdatedTimestamp() {
      PropertyMetadata createdTimestampMetadata = entityMetadata.getCreatedTimestampMetadata();
      PropertyMetadata updatedTimestampMetadata = entityMetadata.getUpdatedTimestampMetadata();
      long millis = System.currentTimeMillis();
      if (createdTimestampMetadata != null) {
        applyAutoTimestamp(createdTimestampMetadata, millis);
      }
      if (updatedTimestampMetadata != null) {
        applyAutoTimestamp(updatedTimestampMetadata, millis);
      }
    }
docs: Marshals both created and updated timestamp fields.