Allow RequestsCookieJar to be updated with cookies from a CookieJar

requests/cookies.py

@@ -258,6 +258,14 @@ class RequestsCookieJar(cookielib.CookieJar, collections.MutableMapping):
         """Deletes a cookie given a name. Wraps cookielib.CookieJar's remove_cookie_by_name()."""
         remove_cookie_by_name(self, name)
 
+    def update(self, other):
+        """Updates this jar with cookies from another CookieJar or dict-like"""
+        if isinstance(other, cookielib.CookieJar):
+            for cookie in other:
+                self.set_cookie(cookie)
+        else:
+            super(RequestsCookieJar, self).update(other)
+
     def _find(self, name, domain=None, path=None):
         """Requests uses this method internally to get cookie values. Takes as args name
         and optional domain and path. Returns a cookie.value. If there are conflicting cookies,