code: private boolean isCorrectVertex() {
  		try {
  			String geomType = service.getIndexService().getGeometryType(service.getGeometry(), index);
  			if (Geometry.LINE_STRING.equals(geomType)) {
  				GeometryIndex temp = service.getIndexService().getPreviousVertex(service.getInsertIndex());
  				return temp.equals(index);
  			} else if (Geometry.LINEAR_RING.equals(geomType)) {
  				return 0 == service.getIndexService().getValue(index);
  			}
  		} catch (GeometryIndexNotFoundException e) {
  			throw new IllegalStateException(e);
  		}
  		return false;
  	}
docs: Stop when clicking on the last vertex for line strings or the first one for linear rings (closing action).
  Double-clicking is now handled in the GeometryIndexInsertcontroller.
  
  @return