public KnowledgeGraphRelationshipTypeDescription( 
   string name,
   IEnumerable<KnowledgeGraphPropertyDescription> propertyDescriptions
)

await QueuedTask.Run(() =>
{
  using (var kg = GetKnowledgeGraph())
  {
    if (kg == null)
      return;

    var entity_name = "PhoneCall";
    var relate_name = "WhoCalledWho";

    //Entity Fields
    var descs1 =
        new List<KnowledgeGraphPropertyDescription>();
    descs1.Add(
      new KnowledgeGraphPropertyDescription("PhoneOwner", FieldType.String));
    descs1.Add(
      new KnowledgeGraphPropertyDescription("PhoneNumber", FieldType.String));
    descs1.Add(
      new KnowledgeGraphPropertyDescription("LocationID", FieldType.BigInteger));
    descs1.Add(
      new KnowledgeGraphPropertyDescription("DateAndTime", FieldType.Date));

    //Relate Fields
    var descs2 =
        new List<KnowledgeGraphPropertyDescription>();
    descs2.Add(
      new KnowledgeGraphPropertyDescription("Foo", FieldType.String));
    descs2.Add(
      new KnowledgeGraphPropertyDescription("Bar", FieldType.String));


    var includeShape = true;//change to false to omit the shape column
    var hasZ = false;
    var hasM = false;

    KnowledgeGraphEntityTypeDescription entityDesc = null;
    KnowledgeGraphRelationshipTypeDescription relateDesc = null;
    if (includeShape)
    {
      var sr = kg.GetSpatialReference();
      var shp_desc = new ShapeDescription(GeometryType.Point, sr)
      {
        HasM = hasM,
        HasZ = hasZ
      };
      entityDesc = new KnowledgeGraphEntityTypeDescription(
        entity_name, descs1, shp_desc);
      relateDesc = new KnowledgeGraphRelationshipTypeDescription(
        relate_name, descs2, shp_desc);
    }
    else
    {
      entityDesc = new KnowledgeGraphEntityTypeDescription(
        entity_name, descs1);
      relateDesc = new KnowledgeGraphRelationshipTypeDescription(
        relate_name, descs2);
    }
    //Run the schema builder
    try
    {
      SchemaBuilder sb = new(kg);
      sb.Create(entityDesc);
      sb.Create(relateDesc);
      //Use the KnowledgeGraph extension method 'ApplySchemaEdits(...)'
      //to refresh the Pro UI
      if (!kg.ApplySchemaEdits(sb))
      {
        var err_msg = string.Join(",", sb.ErrorMessages.ToArray());
        System.Diagnostics.Debug.WriteLine($"Entity/Relate Create error: {err_msg}");
      }
    }
    catch (Exception ex)
    {
      System.Diagnostics.Debug.WriteLine(ex.ToString());
    }
  }
});