Extrinsic 1546-1

{
  "heartbeat": {
    "blockNumber": 1545,
    "sessionIndex": 25,
    "validatorsLen": 4,
    "authorityIndex": 0
  },
  "signature": "0x8ed81549d07069b24fe065668fdf5d48b5eb8603608097280011630dbe9e895035990458e35b3178fdbf9e0dbe983c710c3c91baf818dc92f3aeadee8423d085"
}