Extrinsic 1522-1

{
  "heartbeat": {
    "blockNumber": 1521,
    "sessionIndex": 25,
    "validatorsLen": 1,
    "authorityIndex": 0
  },
  "signature": "0x680679e143078f8e79de82ff12eb45dbdd0437a9112c62de4cceeff2731ce15fbf262934d1de5395c57eedac4c9e1c76a7e84cb8cc995d7f8ee9404564d36d83"
}