code: def get_identities(self, item):
          
  
          if 'authorData' in item['data']['fields']:
              user = self.get_sh_identity(item['data']['fields']['authorData'])
              yield user
  
          if 'ownerData' in item['data']['fields']:
              user = self.get_sh_identity(item['data']['fields']['ownerData'])
              yield user
docs: Return the identities from an item