@spec to_map(LangChain.Chains.LLMChain.t(), map(), any()) ::
  {:ok, map()} | {:error, String.t()}

Write the result to the given map as the value of the given key.

@spec to_map!(LangChain.Chains.LLMChain.t(), map(), any()) :: map() | no_return()

Write the result to the given map as the value of the given key. If invalid, an exception is raised.

@spec to_string(LangChain.Chains.LLMChain.t()) ::
  {:ok, String.t()} | {:error, String.t()}

Return the result of the chain as a string. Returned in an :ok tuple format. An {:error, reason} is returned for various reasons. These include:

• The last message of the chain is not an :assistant message.
• The last message of the chain is incomplete.
• There is no last message.

@spec to_string!(LangChain.Chains.LLMChain.t()) :: String.t() | no_return()

Return the last message's content when it is valid to use it. Otherwise it raises and exception with the reason why it cannot be used. See the docs for LangChain.Utils.ChainResult.to_string/2 for details.