Keep data when adding or removing an entity to/from a cube

Stefan Hering

As-is status: If you either add an entity to a cube or remove an entity from a cube, the cube will be empty afterwards, containing no data anymore.

Idea: It should be possible to keep the data (optional), by either:

• when adding an entity: choose an element of the entity (to be added) to shift all the data of the cube to or
• when removing an entity: just keep the aggregated value.