Extrinsic 16455-1

{
  "heartbeat": {
    "blockNumber": 16454,
    "sessionIndex": 274,
    "validatorsLen": 4,
    "authorityIndex": 3
  },
  "signature": "0xaa4fc64ab31dd8b1c22813ca2f706d8a64dc25cea251f2d3c052d9d9dceb7c42c182be49587c454a37c1484d2b4dfe7349fb3c498df72d47a8b9943cb5ea3e84"
}