Extrinsic 399-1

{
  "heartbeat": {
    "blockNumber": 398,
    "sessionIndex": 6,
    "validatorsLen": 1,
    "authorityIndex": 0
  },
  "signature": "0x5a6b5e0e95ea0b28adff7e9d40d32a63e98d507f79dd5753086a0125fed25049b674fdb2e159fe048e1d901a8a3062ab19dd52c92e1b5ef0fe270124ff88f084"
}