Extrinsic 879-1

{
  "heartbeat": {
    "blockNumber": 877,
    "sessionIndex": 14,
    "validatorsLen": 4,
    "authorityIndex": 1
  },
  "signature": "0x804009c09617b60d9dcc5fb145e0bf5e17f24bcedaacbe6cc392436ab7759d6bbbf135f7cee3bf12ce04bc54cedfef19dd2ea879a5f493d58013adb15f133583"
}