code: public static RightSideEdge to(final String id, final Graph withinGraph) {
  
          // Check sanity
          if (id == null) {
              throw new IllegalArgumentException("Cannot handle null 'id' argument.");
          }
          if (withinGraph == null) {
              throw new IllegalArgumentException("Cannot handle null 'withinGraph' argument.");
          }
  
          // First, assume that the ID is a NodeID.
          // final Statements statements = immediateParent.getStatements();
          final Node node = withinGraph.getStatements().findNode(id, true);
          if (node != null) {
              return new RightSideEdge(node.getNodeID());
          }
  
          // Next, assume that the ID is a Subgraph.
          final Subgraph subgraph = withinGraph.getStatements().findSubgraph(id, true);
          if (subgraph != null) {
              return new RightSideEdge(subgraph);
          }
  
          // All Done.
          return null;
      }
docs: Factory method creating a {@link RightSideEdge} which terminates in the Node or Subgraph with the supplied ID
  and within the supplied Graph.
  
  @param id          A non-null identifier of a NodeID or Subgraph to which this {@link RightSideEdge}
  should go.
  @param withinGraph The non-null Graph which is the ultimate parent of the {@link RightSideEdge} to create.
  @return A newly constructed {@link RightSideEdge} which <strong>is not yet added to any {@link Edge} or
  {@link RightSideEdge}</strong> - or null if no Node or Subgraph with the supplied id was
  found in the withinGraph.