Extrinsic 15555-1

{
  "heartbeat": {
    "blockNumber": 15554,
    "sessionIndex": 259,
    "validatorsLen": 1,
    "authorityIndex": 0
  },
  "signature": "0x4ebe57049c609de26c6b8032efb82f93d5dfa533721d0db4bb555b6587c66e5784b4fb2e1503d0a55d97f0a35125596760ee0e004881b484093c1a5105962d83"
}