nit

Author: jprakash-db

src/databricks/sql/auth/authenticators.py

@@ -1,6 +1,6 @@
 import abc
 import logging
-from typing import Callable, Dict, List
+from typing import Callable, Dict, List, Optional
 from databricks.sql.common.http import HttpHeader
 from databricks.sql.auth.oauth import (
     OAuthManager,
@@ -183,11 +183,11 @@ class AzureServicePrincipalCredentialProvider(CredentialsProvider):
 
     def __init__(
         self,
-        hostname: str,
-        oauth_client_id: str,
-        oauth_client_secret: str,
-        azure_tenant_id: str,
-        azure_workspace_resource_id: str = None,
+        hostname: Optional[str],
+        oauth_client_id: Optional[str],
+        oauth_client_secret: Optional[str],
+        azure_tenant_id: Optional[str],
+        azure_workspace_resource_id: Optional[str] = None,
     ):
         self.hostname = hostname
         self.oauth_client_id = oauth_client_id

src/databricks/sql/auth/oauth.py

@@ -59,7 +59,7 @@ def get_token(self) -> Token:
         pass
 
     @abstractmethod
-    def refresh(self):
+    def refresh(self) -> Token:
         pass
 
 
@@ -334,7 +334,7 @@ def get_token(self) -> Token:
             self.token = self.refresh()
         return self.token
 
-    def refresh(self) -> None:
+    def refresh(self) -> Token:
         headers = {
             HttpHeader.CONTENT_TYPE.value: "application/x-www-form-urlencoded",
         }