Extrinsic 8689-1

{
  "heartbeat": {
    "blockNumber": 8687,
    "sessionIndex": 144,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0xe8e8ecdbec402f4c7a87f6e5e59c168b231ae46f1a5499571c4ad9570bc25d49e39512b5152cdb03944ce49f33b3cf25fd53d65611783eaf43178bb63f60c386"
}