langchain/langchain/chat_models/__init__.py

from langchain.chat_models.anthropic import ChatAnthropic
from langchain.chat_models.azure_openai import AzureChatOpenAI
from langchain.chat_models.openai import ChatOpenAI
from langchain.chat_models.promptlayer_openai import PromptLayerChatOpenAI

__all__ = ["ChatOpenAI", "AzureChatOpenAI", "PromptLayerChatOpenAI", "ChatAnthropic"]