Extrinsic 3398-1

{
  "heartbeat": {
    "blockNumber": 3397,
    "sessionIndex": 56,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0x648527ffe4c238e66a857d0fc32a7297c061ad36ec3c31707542de5929cd257f9feca483f0d54c28f509bc437b72871c38074de14cbd9dcc22f570539fb07c8e"
}