Kugaaa

Thanks for you answer 👍

I am also thinking about it 1. Usually, different businesses will have different parameters, maybe should create different `AiService` 2. Supply method level parameters

I merged the origin/main And [this commit](https://github.com/langchain4j/langchain4j/pull/942/commits/fa130ed814387e0af95a0e276b6a181c8b7f64a6) handle the OpenAi SDK return a `Usage` is null, a NPE may be thrown after the toolSpecifications generate. pertinent code - dev/langchain4j/service/DefaultAiServices.java:128 -...