public void IsNotNull_default_message_row_index()
        {
            PropertyValidator <Row> validator = PropertyValidator <Row> .For(x => x.Key);

            validator
            .SetRowIndex(1)
            .IsNotNull()
            .Validate(new Row()
            {
                Key = null
            });
            Assert.Equal("Row 1 Field Key : Value is mandatory", validator.ValidationErrors[0].ErrorMessage);
        }