Is it possible to configure a proxy server for datapusher?

If I understand correctly when adding a resource (either as a link ot uploading a file) datapusher will try to fetch the contents of the file and the add it to the datastore using the data API.

I wonder is there's some way to configure a proxy server for datapusher to use when fetching files. I already have a global configuration on /etc/enviroment but python doesn't seem to take it into account