code: def execute(self, sources, target):
          
          fields = self._get_fields_list_from_eps(sources)
          feature_set = set(self.feature_names)
          target._ml_fields = list(self._add_field_roles(fields[0], feature_set, self.role, self.augment))
docs: :type sources: list[DFAdapter]
          :type target: DFAdapter