Extrinsic 574-1

{
  "heartbeat": {
    "blockNumber": 573,
    "sessionIndex": 9,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0x34d8122417cf099b6ddbc3ee5b83916ce172a9408c8093d4fd24e934c94dbc5d3575cca5f200608e26c58a5987ef6cc949c6ed3ea3212460b465945fac75d587"
}