Extrinsic 18997-1

{
  "heartbeat": {
    "blockNumber": 18996,
    "sessionIndex": 316,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0xac5f164d434152ac638f080930f46a15f9a8482e62b89c4e9d151ebc95f86051f0b02770932664c3447aad95f0c1d7c1ada0a8f806f0f7bd6946ff60d1d9958e"
}