Method addCallback

frontend/src/services/uploadService.ts:90–97

(type: "start" | "end", callback: () => void)

  }

  addCallback(type: "start" | "end", callback: () => void) {
    if (type == "start") {
      this.callbacks.onStart.add(callback);
    }
    if (type == "end") {
      this.callbacks.onEnd.add(callback);
    }
  }

  removeCallback(type: "start" | "end", callback: () => void) {
    if (type == "start") {