public function getLastDistinctKeywordsGraph()
{
$view = $this->getLastUnitGraph($this->pluginName, __FUNCTION__, "Referrers.getNumberOfDistinctKeywords");
$view->config->translations['Referrers_distinctKeywords'] = ucfirst($this->translator->translate('Referrers_DistinctKeywords'));
$view->config->columns_to_display = array('Referrers_distinctKeywords');
return $this->renderView($view);
}