code: public Set<Node> getCorrelatedNodes(CorrelationIdentifier cid) {
          Set<Node> ret = new HashSet<Node>();
  
          for (Node n : getNodes()) {
              n.findCorrelatedNodes(cid, ret);
          }
  
          return ret;
      }
docs: This method locates any node within the trace that
  is associated with the supplied correlation id.
  
  @param cid The correlation identifier
  @return The nodes that were correlated with the supplied correlation identifier