Extrinsic 21042-1

{
  "heartbeat": {
    "blockNumber": 21041,
    "sessionIndex": 350,
    "validatorsLen": 4,
    "authorityIndex": 1
  },
  "signature": "0x18bd9397c35b5b94b7ea60e68a9c6d4decc8648850aa3adf9bafe4314b27302b8a5bc35e868be827ea4ec29326b1f4fb537566b29bc65ec7159bff459bf8fc84"
}