can't figure out suspend ....

test.js

#!/usr/bin/env node

var
  Q = require('Q'),
  suspend = require('suspend');

function test() {
  var q = Q.defer();
  setTimeout(function() {
    console.log('time out');
    q.resolve('test');
  }, 1000 * 2);
  return q.promise;
}


function process_starter() {
  console.log('before suspend');
  suspend(function*() {
    console.log('before promise');
    var q = yield test();
    // resume.raw();
    console.log('after promise');
    console.log('q:'+q);
  })();
  console.log('after suspend');
};

console.log('before');
var ret = process_starter();
console.log('after');

why "after" come before "after promise" ?