langchain/llms/aleph_alpha.py/AlephAlpha/_call
class AlephAlpha:    def _call(
        self,
        prompt: str,
        stop: Optional[List[str]] = None,
        run_manager: Optional[CallbackManagerForLLMRun] = None,
    ) -> str:
        """Call out to Aleph Alpha's completion endpoint.

        Args:
            prompt: The prompt to pass into the model.
            stop: Optional list of stop words to use when generating.

        Returns:
            The string generated by the model.

        Example:
            .. code-block:: python

                response = alpeh_alpha("Tell me a joke.")
        """
        from aleph_alpha_client import CompletionRequest, Prompt

        params = self._default_params
        if self.stop_sequences is not None and stop is not None:
            raise ValueError(
                "stop sequences found in both the input and default params."
            )
        elif self.stop_sequences is not None:
            params["stop_sequences"] = self.stop_sequences
        else:
            params["stop_sequences"] = stop
        request = CompletionRequest(prompt=Prompt.from_text(prompt), **params)
        response = self.client.complete(model=self.model, request=request)
        text = response.completions[0].completion
        # If stop tokens are provided, Aleph Alpha's endpoint returns them.
        # In order to make this consistent with other endpoints, we strip them.
        if stop is not None or self.stop_sequences is not None:
            text = enforce_stop_tokens(text, params["stop_sequences"])
        return text