private function _logStartTag($tag, $attr, $output_empty)
{
$spaces = str_repeat(' ', count($this->_logStack));
if ($output_empty) {
$this->_logger->debug(sprintf('[%s] O %s <%s/>', $this->_procid, $spaces, $tag));
} else {
$this->_logStack[] = $tag;
$this->_logger->debug(sprintf('[%s] O %s <%s>', $this->_procid, $spaces, $tag));
}
}