Bug title #340
Description
Describe the bug
running the example LangChain.Samples.Prompts throws System.InvalidOperationException : 'Return values have multiple keys, 'run' only supported when one key currently'
Steps to reproduce the bug
set LangChain.Samples.Prompts as startup project and run.
exception will be thrown n LangChain.Base.BaseChain.RunAsync(..)
Expected behavior
No response
Screenshots
NuGet package version
No response
Additional context
No response