text: 'use strict';
  
  const { MeterProvider } = require('@opentelemetry/sdk-metrics-base');
  const { PrometheusExporter } = require('@opentelemetry/exporter-prometheus');
  
  const exporter = new PrometheusExporter(
    {
      startServer: true,
    },
    () => {
      console.log(
        `prometheus scrape endpoint: http://localhost:${PrometheusExporter.DEFAULT_OPTIONS.port}${PrometheusExporter.DEFAULT_OPTIONS.endpoint}`,
      );
    },
  );
  
  const meter = new MeterProvider({
    exporter,
    interval: 1000,
  }).getMeter('example-prometheus');
  
  const requestCounter = meter.createCounter('requests', {
    description: 'Example of a Counter',
  });
  
  const upDownCounter = meter.createUpDownCounter('test_up_down_counter', {
    description: 'Example of a UpDownCounter',
  });
  
  const labels = { pid: process.pid, environment: 'staging' };
  
  setInterval(() => {
    requestCounter.bind(labels).add(1);
    upDownCounter.bind(labels).add(Math.random() > 0.5 ? 1 : -1);
  }, 1000);
  