php - retrieve email address (only) via lists method in Mailchimp API v3.0 -

i starting migration mailchimp api 2.0 - 3.0, , trying replicate methods used before.

one task retrieve of members email addresses on particular list

currently have

$result = $mailchimp->get('/lists/'.$list_id.'/members/'); 

which returns members array, can't figure out how add fields parameter url retrieve fields want, (eg fname, email address)

worked out, on first page

http://developer.mailchimp.com/documentation/mailchimp/guides/get-started-with-mailchimp-api-3/ 

eg, id, email address , merge fields only,...

$result = $mailchimp->get('/lists/'.$list_id.'/members?fields=members.id,members.email_address,members.merge_fields');