Load a chain from LangchainHub or local filesystem.

Loading from LangchainHub:

import { loadChain } from "langchain/chains/load";
const chain = await loadChain("lc://chains/hello-world/chain.json");
const res = await chain.call({ topic: "my favorite color" });

Loading from local filesystem:

import { loadChain } from "langchain/chains/load";
const chain = await loadChain("/path/to/chain.json");

Use newer load method.