Extrinsic 18758-1

{
  "heartbeat": {
    "blockNumber": 18756,
    "sessionIndex": 312,
    "validatorsLen": 4,
    "authorityIndex": 1
  },
  "signature": "0xb087b0ffb315450942cc6e3d41072206e1f3f62380827df80b0ed770fa81b35b1e10c3e96f45f62d044222864010b3b8d5747f155024fded08f5027a0d4a8b80"
}