function createHeadInsertionTransformStreamimport { createHeadInsertionTransformStream } from "https://dotland.deno.dev/x/ultra@v2.1.0/lib/stream.ts"; createHeadInsertionTransformStream(insert: () => Promise<string>): TransformStream<Uint8Array, Uint8Array>Parametersinsert: () => Promise<string>ReturnsTransformStream<Uint8Array, Uint8Array>