public async Task Insert_VariableRows_StillReads()
        {
            var row1 = new Value("pk", "rk1")
            {
                ["col1"] = "val1",
                ["col2"] = "val2"
            };
            var row2 = new Value("pk", "rk2")
            {
                ["col2"] = "val2",
                ["col3"] = "val3"
            };
            await _tables.InsertAsync(_tableName, new[] { row1, row2 });

            Value row11 = await _tables.GetSingleAsync(_tableName, new Key("pk", "rk1"));

            Value row12 = await _tables.GetSingleAsync(_tableName, new Key("pk", "rk2"));


            Assert.Equal("val1", (string)row11["col1"]);
            Assert.Equal("val2", (string)row11["col2"]);

            Assert.Equal("val2", (string)row12["col2"]);
            Assert.Equal("val3", (string)row12["col3"]);
        }