Method Destroy

test/async_worker.cc:70–75

 protected:
  void Execute() override {}
  void Destroy() override {
    assert(this->_secretVal == 24);
    Allocator allocator;
    std::allocator_traits<Allocator>::destroy(allocator, this);
    allocator.deallocate(this, 1);
  }

 private:
  int _secretVal = 24;