Reflect that headers are non-optional in _get_encoding_from_headers().
@@ -155,7 +155,7 @@ def _get_html_response(url, session):
def _get_encoding_from_headers(headers):
- # type: (Optional[ResponseHeaders]) -> Optional[str]
+ # type: (ResponseHeaders) -> Optional[str]
"""Determine if we have any encoding information in our headers.
"""
if headers and "Content-Type" in headers:
