def _fit_current_model()

in ax/modelbridge/generation_strategy.py [0:0]


    def _fit_current_model(self, data: Data) -> None:
        """Instantiate the current model with all available data."""
        # If last generator run's index matches the current step, extract
        # model state from last generator run and pass it to the model
        # being instantiated in this function.
        lgr = self.last_generator_run
        # NOTE: This will not be easily compatible with `GenerationNode`;
        # will likely need to find last generator run per model. Not a problem
        # for now though as GS only allows `GenerationStep`-s for now.
        # Potential solution: store generator runs on `GenerationStep`-s and
        # split them per-model there.
        model_state_on_lgr = {}
        if (
            lgr is not None
            and lgr._generation_step_index == self._curr.index
            and lgr._model_state_after_gen
            and self.model
        ):
            # TODO[drfreund]: Consider moving this to `GenerationStep` or
            # `GenerationNode`.
            model_state_on_lgr = _extract_model_state_after_gen(
                generator_run=lgr,
                model_class=not_none(self.model).model.__class__,
            )

        if not data.df.empty:
            trial_indices_in_data = sorted(data.df["trial_index"].unique())
            logger.debug(f"Fitting model with data for trials: {trial_indices_in_data}")

        self._curr.fit(experiment=self.experiment, data=data, **model_state_on_lgr)
        self._model = self._curr.model_spec.fitted_model