Update comments (#4569)

### What problem does this PR solve?

Add license statement.

### Type of change

- [x] Refactoring

Signed-off-by: Jin Hai <haijin.chn@gmail.com>

sdk/python/ragflow_sdk/modules/chunk.py

@@ -1,3 +1,19 @@
+#
+#  Copyright 2025 The InfiniFlow Authors. All Rights Reserved.
+#
+#  Licensed under the Apache License, Version 2.0 (the "License");
+#  you may not use this file except in compliance with the License.
+#  You may obtain a copy of the License at
+#
+#      http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS,
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+#  See the License for the specific language governing permissions and
+#  limitations under the License.
+#
+
 from .base import Base
 
 
@@ -18,11 +34,8 @@ class Chunk(Base):
                 res_dict.pop(k)
         super().__init__(rag, res_dict)
 
-
-    def update(self,update_message:dict):
-        res = self.put(f"/datasets/{self.dataset_id}/documents/{self.document_id}/chunks/{self.id}",update_message)
+    def update(self, update_message: dict):
+        res = self.put(f"/datasets/{self.dataset_id}/documents/{self.document_id}/chunks/{self.id}", update_message)
         res = res.json()
-        if res.get("code") != 0 :
+        if res.get("code") != 0:
             raise Exception(res["message"])
-
-