inline all messages

zfs_backup/zfs_path.py

@@ -1,7 +1,5 @@
 from __future__ import annotations
 
-from zfs_backup.messages import NOT_VALID_ZFS_PATH
-
 
 class ZFSPath:
     """Represents a path in ZFS.
@@ -79,4 +77,4 @@ class ZFSPath:
     def _sanity_check(elements: list[str]) -> None:
         for item in elements:
             if len(item) == 0:
-                raise ValueError(NOT_VALID_ZFS_PATH)
+                raise ValueError("Not a valid ZFSPath")