Huggingface tokenizer name.
Solar tokenizer is opened in huggingface https://huggingface.co/upstage/solar-pro-tokenizer
ChatUpstage chat model.
To use, you should have the environment variable UPSTAGE_API_KEY set with your
API key or pass it as a named parameter to the constructor.
Example:
from langchain_upstage import ChatUpstage
model = ChatUpstage()