code: def get_groups_from_category(self, category) -> typing.Iterator['Group']:
          
          Mission.validator_group_category.validate(category, 'get_groups_from_category')
          for group in self.groups:
  
              if group.group_category == category:
                  yield group
docs: Args:
              category: group category
  
          Returns: generator over all groups from a specific category in this coalition