Extrinsic 15506-1

{
  "heartbeat": {
    "blockNumber": 15504,
    "sessionIndex": 258,
    "validatorsLen": 4,
    "authorityIndex": 0
  },
  "signature": "0xde3b4e5e2f35970dbf680eaf62a2c49ed78d752bcc2cca1505c97c90ee01350aa4967184e45c3544dfefa8db942053153d7a44cd2bc3ab9c52de290c551c5488"
}