Irule with Multiple URL's

I guess that would be for a redirect to https, I would need something similar to this irule but instead of just two urls, I need it to alternate between 4 urls.

when RULE_INIT { set ::whichone 0 } when HTTP_REQUEST { switch $::whichone { 0 { HTTP::redirect "http://www.test.com” } 1 { HTTP::redirect "http://www.test1.com” } } set ::whichone [expr ! $::whichone]