langchain/experimental/generative_agents/memory.py/GenerativeAgentMemory/_get_topics_of_reflection
class GenerativeAgentMemory:    def _get_topics_of_reflection(self, last_k: int = 50) -> List[str]:
        """Return the 3 most salient high-level questions about recent observations."""
        prompt = PromptTemplate.from_template(
            "{observations}\n\n"
            + "Given only the information above, what are the 3 most salient"
            + " high-level questions we can answer about the subjects in"
            + " the statements? Provide each question on a new line.\n\n"
        )
        observations = self.memory_retriever.memory_stream[-last_k:]
        observation_str = "\n".join([o.page_content for o in observations])
        result = self.chain(prompt).run(observations=observation_str)
        return self._parse_list(result)