Discriminated union representing the possible shapes of an IResponse snapshot.
When streaming is false, body is a buffered Uint8Array | string | null.
When streaming is true, body is a live ReadableStream<Uint8Array>.
{ readonly streaming: false; readonly status: number; readonly headers: Headers; readonly body: Uint8Array | string | null; readonly responseInit?: ResponseSnapshotInit | undefined; }
| { readonly streaming: true; readonly status: number; readonly headers: Headers; readonly body: ReadableStream<Uint8Array>; readonly responseInit?: ResponseSnapshotInit | undefined; }