code: def serialize(self):
          
          if self.action == 'Create':
              payload = self.extra['index'].schema()
          else:
              payload = {
                  'IndexName': self.index_name,
              }
              if self.action == 'Update':
                  payload['ProvisionedThroughput'] = \
                      self.extra['throughput'].schema()
          return {
              self.action: payload
          }
docs: Get the serialized Dynamo format for the update