The "Graphic Group ID" (0070,0295) that is used when converting an AnnObject to a grouped Leadtools.Dicom.DicomAnnotationObject.
Certain LEAD Leadtools.Annotations.Engine.AnnObject are converted to two or more Leadtools.Dicom.DicomAnnotationObject, which are then "grouped" together. These include Leadtools.Annotations.Engine.AnnPolyRulerObject and Leadtools.Annotations.Engine.AnnProtractorObject. The GraphicGroupId is a number that these grouped objects share to identify them as part of a group
For an example, refer to FromAnnContainerToDataSet(DicomDataSet,AnnContainer).