add to node optimizer

Author: Samoed

autointent/nodes/_optimization/_node_optimizer.py

@@ -11,6 +11,7 @@
 import torch
 from optuna.trial import Trial
 from pydantic import BaseModel, Field
+from typing_extensions import assert_never
 
 from autointent import Dataset
 from autointent.context import Context
@@ -84,6 +85,8 @@ def fit(self, context: Context, sampler: SamplerType = "brute") -> None:
             elif sampler == "random":
                 sampler_instance = optuna.samplers.RandomSampler(seed=context.seed)  # type: ignore[assignment]
                 n_trials = n_trials or 10
+            else:
+                assert_never(sampler)
             study = optuna.create_study(direction="maximize", sampler=sampler_instance)
             optuna.logging.set_verbosity(optuna.logging.WARNING)
             obj = partial(self.objective, module_name=module_name, search_space=search_space, context=context)