Extrinsic 18404-1

{
  "heartbeat": {
    "blockNumber": 18403,
    "sessionIndex": 306,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0x0ca38a73e7a47fa44f5b100a56773387a652b4d04203cde819a4a7d9e202e41a9c958d663c5167a45ba1e67db87b765be7093cf405a66483e39d83af6fe3ea84"
}