is passed in, it's assumed to already be a valid JsonSchema.
            For best results, pydantic.BaseModels should have docstrings describing what
            the schema represents and descriptions for the parameters.
        llm: Language model to use, assumed to support the OpenAI function-calling API.
        prompt: BasePromptTemplate to pass to the model.
        output_key: The key to use when returning the output in LLMChain.__call__.
        output_parser: BaseLLMOutputParser to use for parsing model outputs. By default
            will be inferred from the function types. If pydantic.BaseModels are passed
            in, then the OutputParser will try to parse outputs using those. Otherwise
            model outputs will simply be parsed as JSON.
    Returns:
        An LLMChain that will pass the given function to the model.
    Example:
        .. code-block:: python
                from typing import Optional
                from langchain.chains.openai_functions import create_structured_output_chain
                from langchain.chat_models import ChatOpenAI
                from langchain.prompts import ChatPromptTemplate
                from langchain.pydantic_v1 import BaseModel, Field
                class Dog(BaseModel):
                    \"\"\"Identifying information about a dog.\"\"\"
                    name: str = Field(..., description="The dog's name")
                    color: str = Field(..., description="The dog's color")
                    fav_food: Optional[str] = Field(None, description="The dog's favorite food")
                llm = ChatOpenAI(model="gpt-3.5-turbo-0613", temperature=0)
                prompt = ChatPromptTemplate.from_messages(
                    [
                        ("system", "You are a world class algorithm for extracting information in structured formats."),