Extrinsic 18729-1

{
  "heartbeat": {
    "blockNumber": 18727,
    "sessionIndex": 312,
    "validatorsLen": 1,
    "authorityIndex": 0
  },
  "signature": "0xd2dd80aecbe2322ed5dda846ea89226410e63780f5ba90b28807c49c8999fa743607127b08c33ab5e15112126b2472f19e684d72e43c33e6fea65c305fd12c88"
}