Fix type annotation

model.py

@@ -6,8 +6,8 @@ import sys
 
 import PIL.Image
 import torch
-from diffusers import (DDIMPipeline, DDIMScheduler, DDPMPipeline, PNDMPipeline,
-                       PNDMScheduler)
+from diffusers import (DDIMPipeline, DDIMScheduler, DDPMPipeline,
+                       DiffusionPipeline, PNDMPipeline, PNDMScheduler)
 
 HF_TOKEN = os.environ['HF_TOKEN']
 
@@ -39,7 +39,7 @@ class Model:
                                             self.scheduler_type)
 
     def _load_pipeline(self, model_name: str,
-                       scheduler_type: str) -> DDIMPipeline | DDPMPipeline:
+                       scheduler_type: str) -> DiffusionPipeline:
         repo_id = f'hysts/diffusers-anime-faces-{model_name}'
         if scheduler_type == 'DDPM':
             pipeline = DDPMPipeline.from_pretrained(repo_id,
@@ -74,7 +74,7 @@ class Model:
 
         logger.info('--- done ---')
 
-    def _download_all_models(self):
+    def _download_all_models(self) -> None:
         for name in self.MODEL_NAMES:
             self._load_pipeline(name, 'DDPM')