Fix Issue15701 : add .headers attribute to urllib.error.HTTPError
diff --git a/Lib/urllib/error.py b/Lib/urllib/error.py
index c1dfc40..237ed6b 100644
--- a/Lib/urllib/error.py
+++ b/Lib/urllib/error.py
@@ -61,6 +61,14 @@
     def reason(self):
         return self.msg
 
+    @property
+    def headers(self):
+        return self.hdrs
+
+    @headers.setter
+    def headers(self, headers):
+        self.hdrs = headers
+
 # exception raised when downloaded size does not match content-length
 class ContentTooShortError(URLError):
     def __init__(self, message, content):