Extrinsic 4123-1

{
  "heartbeat": {
    "blockNumber": 4122,
    "sessionIndex": 68,
    "validatorsLen": 4,
    "authorityIndex": 3
  },
  "signature": "0x90bf7f3868d65a1bf7a58c10bc7725ded6497eb2f884c9d2e84ae184bdd78c403f3c785f526f21e870430a4479472261943aabbf5646c9f3b5a4dd1a68fcc58f"
}