def mixin(self):
        """
        Add the annotations to the ODM Element (if defined)
        :return: 
        """
        if self.milestones:
            from rwslib.builders.clinicaldata import Annotation, Flag, FlagValue
            annotation = Annotation()
            for codelist, milestones in self.milestones.items():
                for milestone in milestones:
                    annotation << Flag() << FlagValue(milestone, codelist_oid=codelist)
            self.annotations.append(annotation)
Add the annotations to the ODM Element (if defined)
        :return: