Extrinsic 20421-1

{
  "heartbeat": {
    "blockNumber": 20420,
    "sessionIndex": 340,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0x949d35f386e84bfa16793d1b117be6f89135485493ac6fb5df591159bb8a1158281fe929be9f263cd2ddde53317a426cd5181abdee64b6a73f6b2f06ebc4d386"
}