Extrinsic 18581-1

{
  "heartbeat": {
    "blockNumber": 18580,
    "sessionIndex": 309,
    "validatorsLen": 4,
    "authorityIndex": 0
  },
  "signature": "0xd883a5386a68c8912d7e08a11a55ad567c680dfad71af07ff93e9f745d7dd1564db9b9afffdc6bad051302bbaf1c862d14f5f11e85c6f13c6c4b175c9a303885"
}