title: GMail Contexual Gadget - Multiple pattern to match more than one condition
body: <p>i'm developing a simple GMail Contextual Gadget (for now if 2 conditions are met there is a simple "hello world" in the gmail page).
  But i need to match a double condition, and not only one. Because of that, i can't use the precanned extractors (if i use two extractor in the manifest, using the precanned ones, they work on OR condition).</p>
  
  <p>According to <a href="https://groups.google.com/forum/?fromgroups=#!topic/google-apps-developer-blog/JWrEdxBMfvU" rel="nofollow">this article</a> there is a way to match a double condition:</p>
  
  <blockquote>
    <p>Custom extractors allow developers to trigger their gadget when a series of conditions are met. For example, a developer could write an extractor that triggered a gadget only when “Hello world” appeared in the subject <strong>and</strong> “jo...@example.com” was the sender of the email. This allows developers to more finely tune their gadgets, and provide even more relevant contextual information.</p>
  </blockquote>
  
  <p>This is exactly what i need, i need to match if the sender is "xxx@xx.com" <strong>AND</strong> the subject is "zzz".</p>
  
  <p>The problem is that i can't find any references about this problem in the <a href="https://developers.google.com/google-apps/gmail/contextual_gadgets#writing_a_custom_extractor" rel="nofollow">google api page</a></p>
  
  <p>How can i defined a <em>double AND condition</em> in a custom extractor? </p>
  
  <p>Thanks
  Bye</p>