anchor.diff:  `Metric` instance outside of the block executing on the ForkJoinPool, it
   also creates a "thread-safe" type of metric.
   
  +[[exposing-metrics]]
   === Exposing metrics ===
   
   The main method Jet has for exposing the metrics to the outside world is
  
positive.code: processor index.
  |===
  
  === User-defined metrics ===
  
  User-defined metrics are actually a subset of job metrics. What
  
negative.code: 
  Let's look at these 3 broad categories of metrics in detail.
  
  [[imdg-metrics]]
  === IMDG Metrics ===
  There is a wide range of metrics and statistics provided by IMDG:
  
  