public async void Execute(Gateway gateway)
        {
            // 通信実装を毎フレーム呼び出し
            switch (State)
            {
            case GatewayState.GETTING_DREAMS_LIST:
                _existsFiles = FilerOperator.getExistsTextures();
                _dream       = await gateway.GetDreamsData();

                if (_dream != null)
                {
                    State = GatewayState.GETTING_DREAM_TEXTURE_INIT;
                }
                break;

            case GatewayState.GETTING_DREAM_TEXTURE_INIT:
                _image = _dream.images[_counter];
                // 既にローカルにテクスチャが存在する場合はスキップ
                if (_existsFiles != null && _existsFiles.Contains(_image))
                {
                    State = GatewayState.GETTING_DREAM_TEXTURE_FINISHED;
                    break;
                }
                //gateway.SetUrlFromFileName(_image);
                //State = gateway.GetDreamTexture(_image);
                break;

            case GatewayState.GETTING_DREAM_TEXTURE:
                //State = gateway.GetDreamTexture(_image);
                break;

            case GatewayState.GETTING_DREAM_TEXTURE_FINISHED:
                _counter++;
                if (_counter < _dream.images.Length)
                {
                    State = GatewayState.GETTING_DREAM_TEXTURE_INIT;
                }
                else
                {
                    State = GatewayState.GETTING_DREAM_TEXTURES_COMPLETED;
                }
                break;

            case GatewayState.GETTING_DREAM_TEXTURES_COMPLETED:
                break;
            }
        }