code: def set_last_position(self, last_position):
          
          if last_position:
              if isinstance(last_position, six.string_types):
                  last_key = last_position
              else:
                  last_key = last_position.get('last_key', '')
              self.last_position = dict(last_key=last_key)
              self.collection_scanner.set_startafter(last_key)
          else:
              self.last_position = {}
docs: Called from the manager, it is in charge of updating the last position of data commited
          by the writer, in order to have resume support