code: public void incrementCounter(BugChecker bugChecker, String key, int count) {
      statisticsCollector.incrementCounter(statsKey(bugChecker.canonicalName() + "-" + key), count);
    }
docs: Increment the counter for a combination of {@code bugChecker}'s canonical name and {@code key}
  by {@code count}.
  
  <p>e.g.: a key of {@code foo} becomes {@code FooChecker-foo}.