code: void onBuildChildNode(Object childObject, EntityMetadata childMetadata, PersistenceDelegator delegator,
              PersistenceCache pc, Node node, Relation relation)
      {
          Node childNode = generate(childObject, delegator, pc, null);
          if (childNode != null)
          {
              assignNodeLinkProperty(node, relation, childNode);
          }
      }
docs: On building child node
  
  @param childObject
  child object
  @param childMetadata
  child metadata
  @param delegator
  persistence delegator
  @param pc
  persistence cache
  @param node
  node
  @param relation
  entity relation