Extrinsic 18688-1

{
  "heartbeat": {
    "blockNumber": 18687,
    "sessionIndex": 311,
    "validatorsLen": 4,
    "authorityIndex": 3
  },
  "signature": "0x268c839416031d1ff7a0603e55aff6e9f25542c71f960e5f41a1296f075ee37cc0060d82cb9bd7c252c78d62d51c31f6dd2b4ba5d1fd55b54d906b1324d95d85"
}