function isAsync(object) {
      // avoid using `instanceof` here because of IE memory leak issues with host objects
      var async = args[0] && args[0].async;
      return Object(object).constructor == Benchmark && name == 'run' &&
        ((async == null ? object.options.async : async) && support.timeout || object.defer);
    }
Checks if invoking `Benchmark#run` with asynchronous cycles.