FIX linter errors

Author: Griffsano

src/book.py

@@ -21,7 +21,7 @@
 import re
 from collections import defaultdict
 from pathlib import Path
-from typing import Any, Optional, Type
+from typing import Any, Optional
 
 import config
 import misc
@@ -56,7 +56,7 @@ def create_operation(
         coin: str,
         row: int,
         file_path: Path,
-    ) -> Type[tr.Operation]:
+    ) -> tr.Operation:
 
         try:
             Op = getattr(tr, operation)
@@ -70,7 +70,9 @@ def create_operation(
             )
             raise RuntimeError
 
-        return Op(utc_time, platform, change, coin, row, file_path)
+        op = Op(utc_time, platform, change, coin, row, file_path)
+        assert isinstance(op, tr.Operation)
+        return op
 
     def _append_operation(
         self,