Extrinsic 21578-1

{
  "heartbeat": {
    "blockNumber": 21577,
    "sessionIndex": 359,
    "validatorsLen": 4,
    "authorityIndex": 3
  },
  "signature": "0xe855112ad4eec7df71323ca8c41f4a1d455bb3edab31e5d346132b3e9e2de21bf2ccf5e3031349a4e88c8e19d40ed890f49335ebecae321333d9ae9c456ccb8c"
}