title: XSLT: copy attributes from child element
body: <p>Input:</p>
  
  <pre><code> &lt;a q='r'&gt;
     &lt;b x='1' y='2' z='3'/&gt;
     &lt;!-- other a content --&gt;
   &lt;/a&gt;
  </code></pre>
  
  <p>Desired output:</p>
  
  <pre><code> &lt;A q='r' x='1' y='2' z='3'&gt;
     &lt;!-- things derived from other a content, no b --&gt;
   &lt;/A&gt;
  </code></pre>
  
  <p>Could someone kindly give me a recipe?</p>