langchain/experimental/generative_agents/memory.py/GenerativeAgentMemory/load_memory_variables
class GenerativeAgentMemory:    def load_memory_variables(self, inputs: Dict[str, Any]) -> Dict[str, str]:
        """Return key-value pairs given the text input to the chain."""
        queries = inputs.get(self.queries_key)
        now = inputs.get(self.now_key)
        if queries is not None:
            relevant_memories = [
                mem for query in queries for mem in self.fetch_memories(query, now=now)
            ]
            return {
                self.relevant_memories_key: self.format_memories_detail(
                    relevant_memories
                ),
                self.relevant_memories_simple_key: self.format_memories_simple(
                    relevant_memories
                ),
            }

        most_recent_memories_token = inputs.get(self.most_recent_memories_token_key)
        if most_recent_memories_token is not None:
            return {
                self.most_recent_memories_key: self._get_memories_until_limit(
                    most_recent_memories_token
                )
            }
        return {}