chain/exportChainStream

{
  start?: number | null
  stop?: number | null
} | undefined

{
  start: number
  stop: number
  block?: RpcBlockHeader & {
    main: boolean
    head: boolean
    latest: boolean
    /**
     * @deprecated Please use sequence instead
     */
    seq: number
    /**
     * @deprecated Please use previousBlockHash instead
     */
    prev: string
  }
}