registerCounter('search_requests_total', 'The total number of search requests.'); * ``` * * @param PrometheusExporter $exporter */ public function registerMetrics(PrometheusExporter $exporter); /** * Collect metrics data, if need be, before exporting. * * As an example, this may be used to perform time consuming database queries and set the value of a counter * or gauge. */ public function collect(); }