title: Facebook, Querying multiple insights metrics with different periods
body: <p>I can query multiple insights metrics like this:</p>
  
  <p>/insights/page_fans,page_fan_adds,page_impressions_unique</p>
  
  <p>but this returns results for 'page_impressions_unique' with all three periods: day, week, days_28</p>
  
  <p>How can I query multiple metrics while one of them has defined period?
  I tried something likes this:</p>
  
  <p>/insights/page_fans,page_fan_adds,page_impressions_unique/week</p>
  
  <ul>
  <li>but this returns results just for page_impressions_unique/week...</li>
  </ul>