Extrinsic 3220-1

{
  "heartbeat": {
    "blockNumber": 3218,
    "sessionIndex": 53,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0x9086cecce60b7b1f470b3d424dd773129ff3e52878aa7416c7fdf275e3c874144576ee8ccb9349fa4a15c61f8df6c36dced654d68961fffe99c64d059ac9288e"
}