Optional type hints accidentally deleted

Problem:
The optional type hints were accidentally deleted.

Solution:
Added type hints back and added comments in code to keep things in sync.

Signed-off-by: Paul Hewlett <phewlett76@gmail.com>

archivist/archivist.py

@@ -33,6 +33,7 @@
 
 import json
 from os.path import isfile as os_path_isfile
+from typing import Optional
 
 from flatten_dict import flatten
 import requests
@@ -61,6 +62,7 @@
 
 LOGGER = logging.getLogger(__name__)
 
+# also change the type hints in __init__ below
 CLIENTS = {
     "assets": _AssetsClient,
     "events": _EventsClient,
@@ -111,6 +113,14 @@ def __init__(self, url, *, auth=None, cert=None, verify=True):
 
         self._cert = cert
 
+        # keep these in sync with CLIENTS map above
+        self.assets: Optional[_AssetsClient]
+        self.events: Optional[_EventsClient]
+        self.locations: Optional[_LocationsClient]
+        self.attachments: Optional[_AttachmentsClient]
+        self.access_policies: Optional[_AccessPoliciesClient]
+        self.subjects: Optional[_SubjectsClient]
+
     def __getattr__(self, value):
         """Create endpoints on demand"""
         client = CLIENTS.get(value)