Method poll

src/utils/mailbox.ts:48–52

(fn: (msg: Message) => boolean = () => true)

  }

  poll(fn: (msg: Message) => boolean = () => true): Message | undefined {
    const idx = this.queue.findIndex(fn)
    if (idx === -1) return undefined
    return this.queue.splice(idx, 1)[0]
  }

  receive(fn: (msg: Message) => boolean = () => true): Promise<Message> {
    const idx = this.queue.findIndex(fn)