Extrinsic 4577-1

{
  "heartbeat": {
    "blockNumber": 4575,
    "sessionIndex": 76,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0xa65520001951b4685d79deea12b6afc24883aea30ebf0a794bfb2a40121b0d6b0febf62a8f2fc504e1b8ebb814ea7e92b661556de21e690d308eb47a220f378c"
}