检查点保存器

::: langgraph.checkpoint.base options: members: - CheckpointMetadata - Checkpoint - BaseCheckpointSaver - create_checkpoint

::: langgraph.checkpoint.serde.base options: members: - SerializerProtocol - CipherProtocol

::: langgraph.checkpoint.serde.jsonplus options: members: - JsonPlusSerializer

::: langgraph.checkpoint.serde.encrypted options: members: - EncryptedSerializer

::: langgraph.checkpoint.memory

::: langgraph.checkpoint.sqlite

::: langgraph.checkpoint.sqlite.aio

::: langgraph.checkpoint.postgres options: members: - PostgresSaver

::: langgraph.checkpoint.postgres.aio options: members: - AsyncPostgresSaver