Extrinsic 3868-1

{
  "heartbeat": {
    "blockNumber": 3866,
    "sessionIndex": 64,
    "validatorsLen": 4,
    "authorityIndex": 0
  },
  "signature": "0x1240b4910c12475647f2d480650cbe4d5cf48fb896e475b31a3f617f9b545b3acca64d1549aea1f11d6dcf4ab80ce56b4f24b807ce78825e93052942c6cd4783"
}