Extrinsic 8473-1

{
  "heartbeat": {
    "blockNumber": 8472,
    "sessionIndex": 141,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0x1cb57e8520783b1c617828e6d1851947e4860618f0f31e83100c3cc4833c121c82e08d284815ec98e8148c81c63723b94692e4c656e91edcb1b20b9cfa60d58d"
}