title: Combine extend and mixin in with same rules
body: <p>Okey!
  I have couple of extends in sass like</p>
  
  <pre><code>%heading
  %paragraph
  %gutter
  </code></pre>
  
  <p>and so on...</p>
  
  <p>I want to reuse thouse in media queries, but that doesnt work. I know that.</p>
  
  <p>Then i came up with the idea to have all my extends as mixins too. So when i want them in a media query i simply use mixin. for example</p>
  
  <pre><code>.my-widget {
      @extend %gutter;
      @media.... {
          @include gutter-other;
      }
  }
  </code></pre>
  
  <p>and because i dont want to write all my rules again. How do i write my sass then?</p>
  
  <p>I tried</p>
  
  <pre><code>%my-extend, @mixin my-extend {
     ...
  }
  </code></pre>
  
  <p>but that didnt work.</p>
  
  <p><strong>Any ideas how to work with this?</strong></p>