Extrinsic 21279-1

{
  "heartbeat": {
    "blockNumber": 21278,
    "sessionIndex": 354,
    "validatorsLen": 4,
    "authorityIndex": 3
  },
  "signature": "0xda3a7c964f422a66e0b67726fda121157879faa193e00f1f397014eb6354bd365cd7dfd37b47f21eb86e60132c733f86953f689ba0b42bb093d1c867b77ac98a"
}