Extrinsic 3391-1

{
  "heartbeat": {
    "blockNumber": 3389,
    "sessionIndex": 56,
    "validatorsLen": 4,
    "authorityIndex": 0
  },
  "signature": "0xb69e6b926acefd33e6e61e44c66b05d52a4147e03254a4d633199eb5e57f4e2968a1c563c37bd48bc778c1c8a2f88f3995c8e13fe5d410a1f517c80082388782"
}