Extrinsic 16538-1

{
  "heartbeat": {
    "blockNumber": 16536,
    "sessionIndex": 275,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0xa8bc9fa71996f34eb9d81e35079700b4f34b046696489963acbb54c95eec41493c8add616d5c631b69cdcc9c75de3e3809b3c9a08bbcf00295857bd4c4772388"
}