remove unused import

pytube/helpers.py

@@ -4,11 +4,9 @@
 import logging
 import pprint
 import re
-from typing import Optional
 
 from pytube.exceptions import RegexMatchError
 
-
 logger = logging.getLogger(__name__)
 
 

pytube/mixins.py

@@ -38,7 +38,7 @@ def apply_signature(config_args: Dict, fmt: str, js: str) -> None:
     )
     for i, stream in enumerate(stream_manifest):
         try:
-            url = stream["url"]
+            url: str = stream["url"]
         except KeyError:
             if live_stream:
                 raise LiveStreamError("Video is currently being streamed live")