Extrinsic 4000-1

{
  "heartbeat": {
    "blockNumber": 3998,
    "sessionIndex": 66,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0xfa48ec6b0cd2918bebbe50ed740110a336f029cc7de705154ff675b968ca503e12e2322bfdfe894c6db662b0492a20d86e062702b15a0606b5b0091d0bc3b989"
}