Extrinsic 1541-1

{
  "heartbeat": {
    "blockNumber": 1540,
    "sessionIndex": 25,
    "validatorsLen": 1,
    "authorityIndex": 0
  },
  "signature": "0x5af452fe7b78f96d1ae4f10c586c4f8d8d66c01fa3dc148ea13a67efb82e887c5103726eb743f5b06c22712f5588df90dbcbaab5e1841fd79a04f49890f89b86"
}