function output = plus(obj,volumeAdded)
  currentVolumeForUnion = insertVolume(getSmallestCommonBoundingVolume(obj,volumeAdded),obj);
  addedVolumeForUnion = insertVolume(getSmallestCommonBoundingVolume(obj,volumeAdded),volumeAdded);

  output = union(currentVolumeForUnion,addedVolumeForUnion);
end