docs: public static void main(String... args) {
      // Step 1. Enable OpenCensus Metrics.
      try {
        setupOpenCensusAndPrometheusExporter();
      } catch (IOException e) {
        System.err.println("Failed to create and register OpenCensus Prometheus Stats exporter " + e);
        return;
      }
  
      BufferedReader stdin = new BufferedReader(new InputStreamReader(System.in));
  
      while (true) {
        try {
          readEvaluateProcessLine(stdin);
        } catch (IOException e) {
          System.err.println("EOF bye " + e);
          return;
        } catch (Exception e) {
          recordTaggedStat(KEY_METHOD, "repl", M_ERRORS, new Long(1));
          return;
        }
      }
    }