Extrinsic 4448-1

{
  "heartbeat": {
    "blockNumber": 4446,
    "sessionIndex": 74,
    "validatorsLen": 4,
    "authorityIndex": 0
  },
  "signature": "0x6ebfee32bdc3ce7e065fea5bd3eb91ca306a7c20f05f2dd9ba5f9d02ffe28d5f80b01def7641ab721552dc0e6c497c5039cb05376541b008abddf40e43f87585"
}