Extrinsic 671-1

{
  "heartbeat": {
    "blockNumber": 670,
    "sessionIndex": 11,
    "validatorsLen": 4,
    "authorityIndex": 0
  },
  "signature": "0xb210c1ef47f37649dbc1ef5988ec80a4399474c08ff694e8dc11bf27e4bdcd5fa57a1b4d316c4a44db3a2d196bdce560a15823407d0c6e891803ac99f136e98c"
}