code: def fetch_next_block(self):
          
                  
          if self._ex_context is None:
              # initiates execution context for the first time
              self._ex_context = self._create_execution_context()
          
          return self._ex_context.fetch_next_block()
docs: Returns a block of results with respecting retry policy.
          
          This method only exists for backward compatibility reasons. (Because QueryIterable
          has exposed fetch_next_block api).
  
          :return:
              List of results.
          :rtype:
              list