Extrinsic 15426-1

{
  "heartbeat": {
    "blockNumber": 15425,
    "sessionIndex": 257,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0x72803b1b5938de7631720a73f3a7795047cb02c2c60c726832dbfa187604c173f266cc01478487af5074cd070225d537c9446403ff57f544c2e9d6e1aa74af8d"
}