Extrinsic 172709-2

{
  "heartbeat": {
    "blockNumber": 172707,
    "sessionIndex": 2878,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0x28efa98cb4ce9f44dc5fc4490e92b6ece3715f0de1cbe9d7fa616dbd276635751bc73ace61189c40bed80adf6fb4a1e1e55e6cbe3aebc3964111250f19da1585"
}