code: protected void regenerateMetrics() {
      if (isInstrumentationEnabled()) {
        this.inputMeter = Optional.of(this.metricContext.meter(MetricNames.ForkOperatorMetrics.RECORDS_IN_METER));
        this.outputForks = Optional.of(this.metricContext.meter(MetricNames.ForkOperatorMetrics.FORKS_OUT_METER));
        this.forkOperatorTimer = Optional.<Timer>of(this.metricContext.timer(MetricNames.ForkOperatorMetrics.FORK_TIMER));
      } else {
        this.inputMeter = Optional.absent();
        this.outputForks = Optional.absent();
        this.forkOperatorTimer = Optional.absent();
      }
    }
docs: Generates metrics for the instrumentation of this class.