--- a/libervia/server/server.py	Wed Sep 29 17:39:08 2021 +0200
+++ b/libervia/server/server.py	Wed Sep 29 17:39:35 2021 +0200
@@ -23,6 +23,7 @@
 import urllib.request, urllib.error
 import time
 import copy
+from typing import Optional
 from pathlib import Path
 from twisted.application import service
 from twisted.internet import reactor, defer, inotify
@@ -1694,17 +1695,24 @@
             "",
         )
 
-    def getExtBaseURL(self, request, path="", query="", fragment="", scheme=None):
+    def getExtBaseURL(
+            self,
+            request: server.Request,
+            path: str = "",
+            query: str = "",
+            fragment: str = "",
+            scheme: Optional[str] = None,
+            ) -> str:
         """Get external URL according to given elements
 
         external URL is the URL seen by external user
-        @param path(unicode): same as for urlsplit.urlsplit
+        @param path: same as for urlsplit.urlsplit
             path will be prefixed to follow found external URL if suitable
-        @param params(unicode): same as for urlsplit.urlsplit
-        @param query(unicode): same as for urlsplit.urlsplit
-        @param fragment(unicode): same as for urlsplit.urlsplit
-        @param scheme(unicode, None): if not None, will override scheme from base URL
-        @return (unicode): external URL
+        @param params: same as for urlsplit.urlsplit
+        @param query: same as for urlsplit.urlsplit
+        @param fragment: same as for urlsplit.urlsplit
+        @param scheme: if not None, will override scheme from base URL
+        @return: external URL
         """
         split_result = self.getExtBaseURLData(request)
         return urllib.parse.urlunsplit(