Extrinsic 619-1

{
  "heartbeat": {
    "blockNumber": 618,
    "sessionIndex": 10,
    "validatorsLen": 1,
    "authorityIndex": 0
  },
  "signature": "0x3c36d48c7f86e9a5e68ea6a7b76f598248a3a6c88536e86a1581f4dae310ee6d991c135936f60301923a10b85c828b31ce8fafe2a7055d67839cbd95c9532d87"
}