code: public function deleteNodes($xpath)
      {
          if (!is_string($xpath)) {
              throw new InvalidArgumentException(
                  'Argument 1 passed to deleteNodes() must be a string, ' . gettype($xpath) . ' given'
              );
          }
  
          $nodes = $this->_xpath($xpath);
  
          if (isset($nodes[0])) {
              $tmp = dom_import_simplexml($nodes[0]);
  
              if ($tmp->isSameNode($tmp->ownerDocument->documentElement)) {
                  unset($nodes[0]);
              }
          }
  
          foreach ($nodes as $node) {
              $node->deleteSelf();
          }
  
          return count($nodes);
      }
docs: Delete all elements matching a XPath expression
  
  @param    string $xpath XPath expression
  @throws InvalidArgumentException
  @return    integer            Number of nodes removed