code: static Optional<Instant> getOptInstantProperty(Optional<Entity> entity, String property) {
      return entity
          .filter(w -> w.contains(property))
          .map(workflow -> timestampToInstant(workflow.getTimestamp(property)));
    }
docs: Optionally get an {@link Instant} value for an {@link Entity}'s property.
  
  @return an optional containing the property value if it existed, empty otherwise.