title: Find parent with defined attribute wuth LINQ
body: <p>I have variable XElement <em>content</em> =</p>
  
  <pre><code>        "...
           &lt;item text="Name-1" id="1" segment="1" secret-id="Find-Me"&gt;
              &lt;item text="Name-1-1" id="1.1"&gt;
                 &lt;item text="Name-1-1-1" id="1.1.1" /&gt;
                 &lt;item text="Name-1-1-2" id="1.1.2" /&gt;
              &lt;/item&gt;
           &lt;/item&gt;
           ..."
  </code></pre>
  
  <p>I have also an item with <em>id = 1.1.2</em></p>
  
  <p>I need to find the first parent of this item which has attribute <em>segment="1"</em> and get its <em>secret-id</em></p>
  
  <p>How to do this with LINQ?</p>