Extrinsic 3139-1

{
  "heartbeat": {
    "blockNumber": 3138,
    "sessionIndex": 52,
    "validatorsLen": 4,
    "authorityIndex": 3
  },
  "signature": "0xb8d754fafef9dedbb0c4bb9d1065ad637dbd4279d688dd7bec7c638824bd43712f4efd7a14ebd66a102d3341d5cd58dd9474e08a0549800eb0f3241da8bfc08f"
}