The ID uniquely identifies the roadmap item.
* When the RoadmapItem is inserted into the Roadmap via "insertByIndex"
* the default value of the ID is the first available absolute digit that
* has not yet been assigned to other existing RoadmapItems.
When "Interactive" is true the RoadmapItem supports a certain "HyperLabel
* functionality":
* Moving the Mousepointer over the RoadmapItem will change it to a Refhand and
* underline the Label for the time the mousepointer resides over the RoadmapItem.
* Clicking the mousepointer will then notify the Roadmap Container.
* The property Interactive" is readonly because it is adapted from the container of the
* RoadmapItem.
The ID uniquely identifies the roadmap item.
* When the RoadmapItem is inserted into the Roadmap via "insertByIndex"
* the default value of the ID is the first available absolute digit that
* has not yet been assigned to other existing RoadmapItems.
When "Interactive" is true the RoadmapItem supports a certain "HyperLabel
* functionality":
* Moving the Mousepointer over the RoadmapItem will change it to a Refhand and
* underline the Label for the time the mousepointer resides over the RoadmapItem.
* Clicking the mousepointer will then notify the Roadmap Container.
* The property Interactive" is readonly because it is adapted from the container of the
* RoadmapItem.