Extrinsic 4668-2

{
  "heartbeat": {
    "blockNumber": 4666,
    "sessionIndex": 77,
    "validatorsLen": 4,
    "authorityIndex": 3
  },
  "signature": "0x9cf3760ec82de06d1599040020ad84e784092757c8a05289581a651053e7051047a31eb824a7e41244544e2c5c209ddd4c1454a0cb1528a9016df4bc51002a8e"
}