Extrinsic 18640-1

{
  "heartbeat": {
    "blockNumber": 18638,
    "sessionIndex": 310,
    "validatorsLen": 4,
    "authorityIndex": 1
  },
  "signature": "0x242d6bec9f83eb8a03e34d12b73f2e2f0c462bf50233c87e8c64947078cdd329a039a9d8466c3b92d576bded6d199005e3a1660b90b148f99a8a1f0d41b79e82"
}