Should I unref a CamelDataWrapper when I got it from camel_medium_get_content_object()?

Hi,

I am seeing a lot of unref'ing of CamelDataWrapper object as returned
from camel_medium_get_content_object() (mostly in the GW provider). 

I do not see any ref'ing of the return value in
camel_medium_get_content_object() which leads me to believe that any
such unref'ing is wrong. 

Am I correct?

Thanks,
  jules