code: public void setCreatedTimestampMetadata(PropertyMetadata createdTimestampMetadata) {
      if (this.createdTimestampMetadata != null) {
        throwDuplicateAnnotationException(entityClass, CreatedTimestamp.class,
            this.createdTimestampMetadata, createdTimestampMetadata);
      }
      this.createdTimestampMetadata = createdTimestampMetadata;
    }
docs: Sets the created timestamp metadata to the given value.
  
  @param createdTimestampMetadata
  the created timestamp metadata