[mod_python] Multiple cookies (not writing, but reading...)

in all the mailing list archive, i've found many posts asking how to set
multiple cookies.
that's right, it's in the manual, use the method add.

but, if i can write multiple cookies, i can't figure out how i can read
multiple cookies from headers_in.
is there any counterparts to add ? (the manual does not mention it, neither
do the source code for table)

thanks.

--
rien