// First, we acquire a reader that gives an exclusive lock
Web streams has no synchronous path. Even if your source has data ready and your transform is a pure function, you still pay for promise creation and microtask scheduling on every operation. Promises are fantastic for cases in which waiting is actually necessary, but they aren't always necessary. The new API lets you stay in sync-land when that's what you need.，这一点在heLLoword翻译官方下载中也有详细论述
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.，详情可参考爱思助手下载最新版本
Conservator Jonathan Carr said the Thetford find was made "from extremely thin sheets of metal which have become extremely brittle after 2,000 years in the ground".