title: Loading XML string with PowerShell
body: <p>I have defined an XML string using</p>
  
  <pre><code>$str = "&lt;a&gt;&lt;b&gt;&lt;/b&gt;&lt;/a&gt;"
  </code></pre>
  
  <p>Now I want to load it into a [xml] variable to be able to manipulate it's nodes etc. 
  The row below results in an error...</p>
  
  <pre><code>$str = [xml]"&lt;a&gt;&lt;b&gt;&lt;/b&gt;&lt;/a&gt;"
  </code></pre>
  
  <p>How do I do this?</p>