if (res === '') res = '0';
TransformStream creates a readable/writable pair with processing logic in between. The transform() function executes on write, not on read. Processing of the transform happens eagerly as data arrives, regardless of whether any consumer is ready. This causes unnecessary work when consumers are slow, and the backpressure signaling between the two sides has gaps that can cause unbounded buffering under load. The expectation in the spec is that the producer of the data being transformed is paying attention to the writer.ready signal on the writable side of the transform but quite often producers just simply ignore it.
，推荐阅读Line官方版本下载获取更多信息
US says it supports Pakistan's 'right to defend itself' against Afghan Taliban
（一）盗窃、损毁、擅自移动铁路、城市轨道交通设施、设备、机车车辆配件或者安全标志的；