类：TransformStreamDefaultController
🌐 Class: TransformStreamDefaultController
TransformStreamDefaultController 管理 TransformStream 的内部状态。
🌐 The TransformStreamDefaultController manages the internal state
of the TransformStream.
🌐 Class: TransformStreamDefaultController
TransformStreamDefaultController 管理 TransformStream 的内部状态。
🌐 The TransformStreamDefaultController manages the internal state
of the TransformStream.