Extrinsic 1175-1

{
  "heartbeat": {
    "blockNumber": 1173,
    "sessionIndex": 19,
    "validatorsLen": 4,
    "authorityIndex": 0
  },
  "signature": "0xd00487e82902b672919b1c9f43bb81ee55d3de7731c11e0649fe1a789dac42556c62b706f200d7fec9431ce0f099247eaccf793091faddb2a9077c9970ebb48c"
}