Extrinsic 4422-1

{
  "heartbeat": {
    "blockNumber": 4420,
    "sessionIndex": 73,
    "validatorsLen": 4,
    "authorityIndex": 0
  },
  "signature": "0x8e86c7529503c93835b1469bb1e4d0a36386f95ea0cdccd65d794a35a46f782a137d22bfa1d85da59aa76aca56d551884065d7316c554c343d9d53d78ca31886"
}