code: public ManagementGroupEdge getForwardEdge(final int index) {
  
  		if (index < this.forwardEdges.size()) {
  			return this.forwardEdges.get(index);
  		}
  
  		return null;
  	}
docs: Returns the group edge which leaves this group vertex at the given index.
  
  @param index
  the index of the group edge
  @return the group edge which leaves this group vertex at the given index or <code>null</code> if no such group
  edge exists