code: @Exported
      public int getTotalExecutors() {
          int r=0;
          for (Computer c : get_all()) {
              if(c.isOnline())
                  r += c.countExecutors();
          }
          return r;
      }
docs: Number of total {@link Executor}s that belong to this label that are functioning.
  <p>
  This excludes executors that belong to offline nodes.