Extrinsic 880-1

{
  "heartbeat": {
    "blockNumber": 879,
    "sessionIndex": 14,
    "validatorsLen": 1,
    "authorityIndex": 0
  },
  "signature": "0x26f17b308d7c7abe152bddd47c7dc6a770c5b11cce7fa4e66f73b009e334546f2b4467b1428b29d91ba04f802dc6f48e84ad8a66291ac7b51e7d6692bd0dc480"
}