public void addPrefix(String prefix, String namespace) {
        prefixes.put(prefix, namespace);
    }
Parser for a very simple XPath subset. Only the following XPath constructs
(with namespaces) are supported:
<ul>
  <li><code>.../node()</code></li>
  <li><code>.../text()</code></li>
  <li><code>.../@*</code></li>
  <li><code>.../@name</code></li>
  <li><code>.../*...</code></li>
  <li><code>.../name...</code></li>
  <li><code>...//*...</code></li>
  <li><code>...//name...</code></li>
</ul>
<p>
In addition the non-abbreviated <code>.../descendant::node()</code>
construct can be used for cases where the descendant-or-self axis
used by the <code>...//node()</code> construct is not appropriate.
tika-core/src/main/java/org/apache/tika/sax/xpath/XPathParser.java