Extrinsic 16722-1

{
  "heartbeat": {
    "blockNumber": 16721,
    "sessionIndex": 278,
    "validatorsLen": 1,
    "authorityIndex": 0
  },
  "signature": "0x76b3317770cb94e33236f951555b11f099dd42eb015bcfe02885255af8a8ed5ada22b66d0f55d93e664ef8e66ee4bc848150221b9e18fd47944570222336c280"
}