Extrinsic 8739-1

{
  "heartbeat": {
    "blockNumber": 8738,
    "sessionIndex": 145,
    "validatorsLen": 4,
    "authorityIndex": 0
  },
  "signature": "0x48a1f8e6098370f9891a18f115b04119885a70abb310fd0c914c578ad74f395e448005c7e36ed4a0a161dffe41e773521ace85d410e251afe669d033a267c38b"
}