code: public void observe(CheckedRunnable runnable, CheckedRunnable onSuccess) {
          service.executeAsynchronously(wrap(runnable, onSuccess), config);
      }
docs: Invokes runnable asynchronously with respecting circuit logic and cache
  logic if configured. If callable completed with success then the
  {@code onSuccess} method is called.
  
  @param runnable method fired by executor
  @param onSuccess method fired if callable is completed with success