urllib2.urlopen(req).info() object

[eli li]

The call "urllib2.urlopen(req).info()" returns an object similar to the
dictionary, but it can have muliple values for some key. For example:

Content-Type: text/html
Set-Cookie: A=M
Set-Cookie: WEBTRENDS_ID=192.168.120.21
Set-Cookie: SINFO=ca9e
Via: 1.1 colosus1 (NetCache NetApp/5.3R2D4)

How can I retrive all values related to 'Set-Cookie' key?