moved functions to shared folder

shared/data_store/__init__.py

@@ -1,6 +1,6 @@
-from __future__ import annotations
-
 from .connect import connect
 from .delete import delete
 from .get import get
+from .get_image import get_image
 from .put import put
+from .put_image import put_image

shared/data_store/get.py

@@ -1,5 +1,4 @@
 """Definition of get function."""
-from __future__ import annotations
 
 import os
 from io import BytesIO
@@ -14,8 +13,7 @@ def get(
     """Get buffer from bucket in MinIO."""
     assert isinstance(client, Minio)
     assert isinstance(object_name, str)
-    bucket_name = os.getenv('MINIO_BUCKET_NAME', default=None)
-    assert isinstance(bucket_name, str)
+    bucket_name = os.getenv('MINIO_BUCKET_NAME')
     # get buffer
     try:
         response = client.get_object(bucket_name, object_name)