title: Checking presence of attribute with cts:query
body: <p><code>cts:element-query(xs:QName("elm"),cts:and-query(()))</code> will give all the fragments where the element <strong>elm</strong> is present.</p>
  
  <p>Similarly if I want all documents where an attribute(say <strong>atr</strong>) is present under <strong>elm</strong> what would I have to do?</p>
  
  <p><code>cts:element-attribute-value-query()</code> requires that I pass a value to match against the attribute value. But I want to check only the existence of the attribute irrespective of what value it contains.</p>