Method AsyncProgressWorkerBase

nan.h:2220–2225

class AsyncProgressWorkerBase : public AsyncBareProgressWorker<T> {
 public:
  explicit AsyncProgressWorkerBase(
      Callback *callback_,
      const char* resource_name = "nan:AsyncProgressWorkerBase")
      : AsyncBareProgressWorker<T>(callback_, resource_name), asyncdata_(NULL),
        asyncsize_(0) {
  }

  virtual ~AsyncProgressWorkerBase() {
    delete[] asyncdata_;