public RowHandle( 
   RowToken token
)

{
  var mv = MapView.Active;
  var createRel = await QueuedTask.Run(() =>
  {
    //This example uses a KnowledgeGraphRelationshipDescription
    var edit_op = new EditOperation()
    {
      Name = "Create entities and a relationship using a KG relate desc",
      SelectNewFeatures = true
    };

    //We are just going to use mapmembers in this example
    //we could equally use feature classes/tables
    var kg_layer = mv.Map.GetLayersAsFlattenedList()?
                  .OfType<ArcGIS.Desktop.Mapping.KnowledgeGraphLayer>().First();
    //From the KG Layer get the relevant child feature layer(s) and/or standalone
    //table(s)
    var org_fl = kg_layer.GetLayersAsFlattenedList().OfType<FeatureLayer>()
                    .First(child_layer => child_layer.Name == "Organization");

    var person_stbl = kg_layer.GetStandaloneTablesAsFlattenedList()
                    .First(child_layer => child_layer.Name == "Person");

    var rel_stbl = kg_layer.GetStandaloneTablesAsFlattenedList()
                    .First(child_layer => child_layer.Name == "HasEmployee");

    var attribs = new Dictionary<string, object>();

    //New Organization
    attribs["Name"] = "Acme Ltd.";
    attribs["Description"] = "Specializes in household items";
    attribs["SHAPE"] = mv.Extent.Center;//whatever is its location

    //Add it to the operation - we need the rowtoken
    var rowtoken_org = edit_op.Create(org_fl, attribs);

    attribs.Clear();//we are going to re-use the dictionary

    //New Person
    attribs["Name"] = "Bob";
    attribs["Age"] = "41";
    attribs["Skills"] = "Plumbing, Framing, Flooring";

    //Add it to the operation
    var rowtoken_person = edit_op.Create(person_stbl, attribs);

    attribs.Clear();

    //Create the new relationship using a KnowledgeGraphRelationshipDescription
    //Row handles act as the placeholders for the TO BE created new entities that will
    //be related
    var src_row_handle = new RowHandle(rowtoken_org);
    var dest_row_handle = new RowHandle(rowtoken_person);

    //Add any extra attribute information for the relation as needed
    attribs["StartDate"] = new DateTimeOffset(DateTime.Now);

    var rel_desc = new KnowledgeGraphRelationshipDescription(
                                src_row_handle, dest_row_handle, attribs);

    //Add the relate description to the edit operation
    edit_op.Create(rel_stbl, rel_desc);

    //Execute the create of the entities and relationship
    return edit_op.Execute();
  });
}

{
  // This routine creates a pole and a transformer bank, and then creates a structural attachment association between them, all in a single edit operation
  static void CreateUNFeaturesAndAssociations(FeatureLayer transformerBankLayer,
  Dictionary<string, object> transformerBankAttributes, FeatureLayer poleLayer,
  Dictionary<string, object> poleAttributes)
  {
    // Create an EditOperation
    EditOperation editOperation = new EditOperation();
    editOperation.Name = "Create pole; create transformer bank; attach transformer bank to pole";

    // Create the transformer bank
    RowToken transformerBankToken = editOperation.Create(transformerBankLayer, transformerBankAttributes);

    // Create a pole
    RowToken poleToken = editOperation.Create(poleLayer, poleAttributes);

    // Create a structural attachment association between the pole and the transformer bank
    RowHandle poleHandle = new RowHandle(poleToken);
    RowHandle transformerBankHandle = new RowHandle(transformerBankToken);

    AssociationDescription poleAttachment =
      new AssociationDescription(AssociationType.Attachment, poleHandle, transformerBankHandle);

    editOperation.Create(poleAttachment);

    // Execute the EditOperation
    editOperation.Execute();
  }
}