public async Task QueryMixed_main_index()
        {
            // arrange
            var id      = GetRandomString(10);
            var record1 = new MyRecord {
                Id    = id,
                SubId = GetRandomString(10),
                Value = "Hello"
            };
            await Table.PutItemAsync(MyDataModel.GetPrimaryKey(record1), record1);

            var record2 = new MyOtherRecord {
                Id    = id,
                SubId = GetRandomString(10),
                Name  = "Bob"
            };
            await Table.PutItemAsync(MyDataModel.GetPrimaryKey(record2), record2);

            // act
            var result = await Table.Query(MyDataModel.SelectMyRecordsAndMyOtherRecords(record1.Id), consistentRead : true)
                         .ExecuteAsync();

            // assert
            result.Should().HaveCount(2);
            result.Should().ContainEquivalentOf(record1);
            result.Should().ContainEquivalentOf(record2);
        }
 public static DynamoPrimaryKey <MyOtherRecord> GetPrimaryKey(MyOtherRecord record) => MyOtherRecordPrimaryKey(record.Id, record.SubId);