Extrinsic 18939-1

{
  "heartbeat": {
    "blockNumber": 18938,
    "sessionIndex": 315,
    "validatorsLen": 4,
    "authorityIndex": 3
  },
  "signature": "0xc8194227255d66fa9b6036f094a6b1691e5c2b08d1a2f989a887dce644ebf64f3cd0be28c8eb3ceba135d939545500014290f00a0260d1fab128c3e5c436288a"
}