Customizing the widget.xsd file when creating a custom widget

Hi All. I am creating a custom widget and I would like to show a label or static text in my properties. For this I tried to add an element in my properties of widget.xsd file and accessing it in my xml file. After compiling, when trying access the widget in application it is showing error like The element 'properties' in namespace 'http://www.mendix.com/widget/1.0/' has invalid child element 'label' in namespace 'http://www.mendix.com/widget/1.0/'. List of possible elements expected: 'property' in namespace 'http://www.mendix.com/widget/1.0/'. So is there a possibility of customizing widget.xsd file.

Thank you.