public static bool ApplySchemaEdits( 
   KnowledgeGraph kg,
   SchemaBuilder schemaBuilder
)

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());
    }
  }
});

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

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

    var entityDesc = new KnowledgeGraphEntityTypeDescription(entity_name);
    var relateDesc = new KnowledgeGraphRelationshipTypeDescription(relate_name);

    //Run the schema builder
    try
    {
      SchemaBuilder sb = new(kg);
      sb.Delete(entityDesc);
      sb.Delete(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 Delete error: {err_msg}");
      }
    }
    catch (Exception ex)
    {
      System.Diagnostics.Debug.WriteLine(ex.ToString());
    }
  }
});

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

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

    var kvp_entity = kg.GetDataModel().GetEntityTypes()
         .First(r => r.Key == entity_name);
    var kvp_relate = kg.GetDataModel().GetRelationshipTypes()
                   .First(r => r.Key == relate_name);

    //Let's delete one field and add a new one from each
    //A field gets deleted implicitly if it is not included in the list of
    //fields - or "properties" in this case....so we will remove the last
    //property from the list
    var entity_props = kvp_entity.Value.GetProperties().Reverse().Skip(1).Reverse();
    var prop_descs = new List<KnowledgeGraphPropertyDescription>();

    foreach (var prop in entity_props)
    {
      if (prop.FieldType == FieldType.Geometry)
      {
        continue;//skip shape
      }
      var prop_desc = new KnowledgeGraphPropertyDescription(prop);
      prop_descs.Add(prop_desc);
    }
    //deal with shape - we need to keep it
    //SchemaBuilder deletes any field not included in the "modify" list
    ShapeDescription shape_desc = null;
    if (kvp_entity.Value.GetIsSpatial())
    {
      var geom_def = kvp_entity.Value.GetShapeDefinition();
      var shape_name = kvp_entity.Value.GetShapeField();
      shape_desc = new ShapeDescription(
        shape_name, geom_def.geometryType, geom_def.sr);
    }
    //add the new entity property
    prop_descs.Add(
      KnowledgeGraphPropertyDescription.CreateStringProperty("foo", 10));
    //make a description for the entity type - ok if shape_desc is null
    var entityDesc = new KnowledgeGraphEntityTypeDescription(
      entity_name, prop_descs, shape_desc);

    //Add the entity type description to the schema builder using 'Modify'
    SchemaBuilder sb = new(kg);
    sb.Modify(entityDesc);

    //Repeat for the relationship - assuming we have at least one custom attribute field
    //that can be deleted on our relationship schema...
    var rel_props = kvp_relate.Value.GetProperties().Reverse().Skip(1).Reverse();
    var rel_prop_descs = new List<KnowledgeGraphPropertyDescription>();

    foreach (var prop in rel_props)
    {
      if (prop.FieldType == FieldType.Geometry)
      {
        continue;//skip shape
      }
      var prop_desc = new KnowledgeGraphPropertyDescription(prop);
      rel_prop_descs.Add(prop_desc);
    }
    //deal with shape - we need to keep it
    //SchemaBuilder deletes any field not included in the "modify" list
    ShapeDescription shape_desc_rel = null;
    if (kvp_relate.Value.GetIsSpatial())
    {
      var geom_def = kvp_relate.Value.GetShapeDefinition();
      var shape_name = kvp_relate.Value.GetShapeField();
      shape_desc_rel = new ShapeDescription(
        shape_name, geom_def.geometryType, geom_def.sr);
    }
    //add a new relationship property
    rel_prop_descs.Add(
      KnowledgeGraphPropertyDescription.CreateStringProperty("bar", 10));
    //make a description for the relationship type - ok if shape_desc is null
    var relDesc = new KnowledgeGraphRelationshipTypeDescription(
      relate_name, rel_prop_descs, shape_desc_rel);

    //Add the relationship type description to the schema builder using 'Modify'
    sb.Modify(relDesc);

    //Run the schema builder
    try
    {
      //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 Modify error: {err_msg}");
      }
    }
    catch (Exception ex)
    {
      System.Diagnostics.Debug.WriteLine(ex.ToString());
    }
  }
});

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

        var entity_name = "Fruit";

        //Domains are managed on the GDB objects...
        var fruit_fc = kg.OpenDataset<FeatureClass>(entity_name);
        var fruit_fc_def = fruit_fc.GetDefinition();

        var fieldFruitTypes = fruit_fc_def.GetFields()
              .FirstOrDefault(f => f.Name == "FruitTypes");
        var fieldShelfLife = fruit_fc_def.GetFields()
            .FirstOrDefault(f => f.Name == "ShelfLife");

        //Create a coded value domain and add it to a new field
        var fruit_cvd_desc = new CodedValueDomainDescription(
          "FruitTypes", FieldType.String, 
          new SortedList<object, string> {
                          { "A", "Apple" },
                          { "B", "Banana" },
                          { "C", "Coconut" }
          })  {
            SplitPolicy = SplitPolicy.Duplicate,
            MergePolicy = MergePolicy.DefaultValue
        };

        //Create a Range Domain and add the domain to a new field description also
        var shelf_life_rd_desc = new RangeDomainDescription(
                                      "ShelfLife", FieldType.Integer, 0, 14);

        var sb = new SchemaBuilder(kg);
        sb.Create(fruit_cvd_desc);
        sb.Create(shelf_life_rd_desc);

        //Create the new field descriptions that will be associated with the
        //"new" FruitTypes coded value domain and the ShelfLife range domain
        var fruit_types_fld = new ArcGIS.Core.Data.DDL.FieldDescription(
                                      "FruitTypes", FieldType.String);
        fruit_types_fld.SetDomainDescription(fruit_cvd_desc);

        //ShelfLife will use the range domain
        var shelf_life_fld = new ArcGIS.Core.Data.DDL.FieldDescription(
"ShelfLife", FieldType.Integer);
        shelf_life_fld.SetDomainDescription(shelf_life_rd_desc);

        //Add the descriptions to the list of field descriptions for the
        //fruit feature class - Modify schema needs _all_ fields to be included
        //in the schema, not just the new ones to be added.
        var fruit_fc_desc = new FeatureClassDescription(fruit_fc_def);

        var modified_fld_descs = new List<ArcGIS.Core.Data.DDL.FieldDescription>(
          fruit_fc_desc.FieldDescriptions);

        modified_fld_descs.Add(fruit_types_fld);
        modified_fld_descs.Add(shelf_life_fld);

        //Create a feature class description to modify the fruit entity
        //with the new fields and their associated domains
        var updated_fruit_fc =
          new FeatureClassDescription(entity_name, modified_fld_descs,
                                      fruit_fc_desc.ShapeDescription);

        //Add the modified fruit fc desc to the schema builder
        sb.Modify(updated_fruit_fc);

        //Run the schema builder
        try
        {
          if (!kg.ApplySchemaEdits(sb))
          {
            var err_msg = string.Join(",", sb.ErrorMessages.ToArray());
            System.Diagnostics.Debug.WriteLine($"Create domains error: {err_msg}");
          }
        }
        catch (Exception ex)
        {
          System.Diagnostics.Debug.WriteLine(ex.ToString());
        }
      }
    });