public KnowledgeGraphRelationshipDescription( 
   RowHandle origin,
   RowHandle destination,
   IReadOnlyDictionary<string,object> attributes
)

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"] = org_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();
});