If not specified, the default credential profile or, if on an EC2 instance,
    credentials from IMDS will be used.
    See: https://boto3.amazonaws.com/v1/documentation/api/latest/guide/credentials.html
    """
    content_handler: LLMContentHandler
    """The content handler class that provides an input and
    output transform functions to handle formats between LLM
    and the endpoint.
    """
    """
     Example:
        .. code-block:: python
        from langchain.llms.sagemaker_endpoint import LLMContentHandler
        class ContentHandler(LLMContentHandler):
                content_type = "application/json"
                accepts = "application/json"
                def transform_input(self, prompt: str, model_kwargs: Dict) -> bytes:
                    input_str = json.dumps({prompt: prompt, **model_kwargs})
                    return input_str.encode('utf-8')
                
                def transform_output(self, output: bytes) -> str:
                    response_json = json.loads(output.read().decode("utf-8"))
                    return response_json[0]["generated_text"]
    """
    model_kwargs: Optional[Dict] = None
    """Key word arguments to pass to the model."""
    endpoint_kwargs: Optional[Dict] = None
    """Optional attributes passed to the invoke_endpoint
    function. See `boto3`_. docs for more info.
    .. _boto3: <https://boto3.amazonaws.com/v1/documentation/api/latest/index.html>
    """
    class Config:
        """Configuration for this pydantic object."""
        extra = Extra.forbid
    @root_validator()
    def validate_environment(cls, values: Dict) -> Dict:
        """Dont do anything if client provided externally"""
        if values.get("client") is not None: