interface UnderlyingSourceimport { type UnderlyingSource } from "https://deno.land/x/evt@v2.3.1/lib/types/lib.dom.ts"; Type ParametersoptionalR = anyPropertiesoptionalcancel: ReadableStreamErrorCallbackoptionalpull: ReadableStreamDefaultControllerCallback<R>optionalstart: ReadableStreamDefaultControllerCallback<R>optionaltype: undefined