Extrinsic 761-1

{
  "heartbeat": {
    "blockNumber": 760,
    "sessionIndex": 12,
    "validatorsLen": 4,
    "authorityIndex": 3
  },
  "signature": "0x602bb00d6a5871abc3cb377d345fe015d22f8245e6789be758ee5fccdf1f6673fbe15721f26e3d3d7fe65958164f9d343d7b053a7bc06b76539989403f350d80"
}