docs: public HystrixCommandExecutionHook getCommandExecutionHook() {
          if (commandExecutionHook.get() == null) {
              // check for an implementation from Archaius first
              Object impl = getPluginImplementation(HystrixCommandExecutionHook.class);
              if (impl == null) {
                  // nothing set via Archaius so initialize with default
                  commandExecutionHook.compareAndSet(null, HystrixCommandExecutionHookDefault.getInstance());
                  // we don't return from here but call get() again in case of thread-race so the winner will always get returned
              } else {
                  // we received an implementation from Archaius so use it
                  commandExecutionHook.compareAndSet(null, (HystrixCommandExecutionHook) impl);
              }
          }
          return commandExecutionHook.get();
      }