code: def get(self, resource_manager, identities):
          
          m = self.resolve(resource_manager.resource_type)
          params = {}
          client_filter = False
  
          # Try to formulate server side query
          if m.filter_name:
              if m.filter_type == 'list':
                  params[m.filter_name] = identities
              elif m.filter_type == 'scalar':
                  assert len(identities) == 1, "Scalar server side filter"
                  params[m.filter_name] = identities[0]
          else:
              client_filter = True
  
          resources = self.filter(resource_manager, **params)
          if client_filter:
              # This logic was added to prevent the issue from:
              # https://github.com/capitalone/cloud-custodian/issues/1398
              if all(map(lambda r: isinstance(r, six.string_types), resources)):
                  resources = [r for r in resources if r in identities]
              else:
                  resources = [r for r in resources if r[m.id] in identities]
  
          return resources
docs: Get resources by identities