docs: def build_query_fragment(query):
      """
      <query xmlns="http://basex.org/rest">
          <text><![CDATA[ (//city/name)[position() <= 5] ]]></text>
      </query>
      """
      root = etree.Element('query', nsmap={None: 'http://basex.org/rest'})
      text = etree.SubElement(root, 'text')
      text.text = etree.CDATA(query.strip())
      return root