How to use the mlblocks.parsers.import_object function in mlblocks

def build_mlblock_model(self, fixed_hyperparameters, tunable_hyperparameters):
        """Build the model for this primitive block.

        Args:
            fixed_hyperparameters: The fixed hyperparameters to build
                this model with. Should be specified as a dict mapping
                fixed hyperparameter names to their corresponding
                values.
            tunable_hyperparameters: The tunable hyperparameters to
                build this model with. Should be specified as a dict
                mapping hyperparameter name to MLHyperparam object.

        Returns:
            The model instance of this primitive block.
        """
        block_class = import_object(self.metadata['class'])

        model_kwargs = fixed_hyperparameters.copy()
        model_kwargs.update({
            hp_name: tunable_hyperparameters[hp_name].value
            for hp_name in tunable_hyperparameters
        })

        return block_class(**model_kwargs)