code: def set_result(self, result):
          
          # Sanity check: A future can only complete once.
          if self.done():
              raise RuntimeError("set_result can only be called once.")
  
          # Set the result and trigger the future.
          self._result = result
          self._trigger()
docs: Set the result of the future to the provided result.
  
          Args:
              result (Any): The result