code: public int start() throws Exception {
        if(isStarted.compareAndSet(false, true)) {
           try {
              for(Reporter reporter : reporters) {
                 reporter.start();
              }
           } catch(Exception e) {
              stop();
              throw e;
           }
        }
        return reporters.size();
     }
docs: Starts all reporters.
  @return The number of configured reporters.
  @throws Exception on start error.