                   (numeric) The block height or index
  "version" : n,                  (numeric) The block version
  "versionHex" : "hex",           (string) The block version formatted in hexadecimal
  "merkleroot" : "hex",           (string) The merkle root
  "tx" : [                        (json array) The transaction ids
    "hex",                        (string) The transaction id
    ...
  ],
  "time" : xxx,                   (numeric) The block time expressed in UNIX epoch time
  "mediantime" : xxx