Extrinsic 400703-1

{
  "heartbeat": {
    "blockNumber": 400702,
    "sessionIndex": 6678,
    "validatorsLen": 1,
    "authorityIndex": 0
  },
  "signature": "0xaeae652b2623e15c3d655b59d7617990a0a15f1b73beb172dd4679500b57a64153bf745db0540b1a5e66c55c25153ac6a1c0e374c2ed457a666edf24374ac888"
}