Extrinsic 619-1

{
  "heartbeat": {
    "blockNumber": 618,
    "sessionIndex": 10,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0xb4d171bd776e8e9ef624bef5699d5a1b3c8f96d29ab3ebd48d06c0576b87f95e992f45fa2d39a11b6a19265a00bd3c72b0f5f2e38ba5d591b00fea582a4c788e"
}