Extrinsic 18273-1

{
  "heartbeat": {
    "blockNumber": 18271,
    "sessionIndex": 304,
    "validatorsLen": 4,
    "authorityIndex": 1
  },
  "signature": "0xae172bd8e6f62b8076fbd8f3001b6738d4791f86472214194650c48bb8f7421df540b6d737860fa737fa26983ee21784ee5e01e04f71e61d74c00875f1c7c381"
}