code: void collectGroupVertices(final List<ManagementGroupVertex> groupVertices) {
  
  		final Iterator<ManagementGroupVertex> it = this.groupVertices.iterator();
  
  		while (it.hasNext()) {
  			groupVertices.add(it.next());
  		}
  	}
docs: Adds all management group vertices contained in this stage to the given list.
  
  @param groupVertices
  the list to which the group vertices in this stage shall be added