[NFC] polish applications/Chat/coati/models/base/actor.py code style (#4248)

applications/Chat/coati/models/base/actor.py

@@ -21,16 +21,13 @@ class Actor(LoRAModule):
         self.model = model
         self.convert_to_lora()
 
-    def forward(self,
-                input_ids: torch.LongTensor,
-                attention_mask: Optional[torch.Tensor] = None,
-                **model_kwargs,  # HACK: `generate` method may pass more kwargs
-                ) -> torch.Tensor:
+    def forward(
+            self,
+            input_ids: torch.LongTensor,
+            attention_mask: Optional[torch.Tensor] = None,
+            **model_kwargs,    # HACK: `generate` method may pass more kwargs
+    ) -> torch.Tensor:
         """Returns model output.
         """
-        output = self.model(
-            input_ids,
-            attention_mask=attention_mask,
-            **model_kwargs
-        )
+        output = self.model(input_ids, attention_mask=attention_mask, **model_kwargs)
         return output