langchain

d4d64daa - Mask API key for baidu qianfan (#14281)

Mask API key for baidu qianfan (#14281) Description: This PR masked baidu qianfan - Chat_Models API Key and added unit tests. Issue: the issue langchain-ai#12165. Tag maintainer: @eyurtsev --------- Co-authored-by: xiayi <xiayi@bytedance.com>