Extrinsic 1302-1

{
  "heartbeat": {
    "blockNumber": 1299,
    "sessionIndex": 21,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0xdeb101f706f482269873e84f2c7ba57f9b25cfc3c413b7964a20cfdfddcde6514254d632b9d8af405c958fac4b5eaab216c36b902f0ccc13e6d183349f81f388"
}