Extrinsic 1291-1

{
  "heartbeat": {
    "blockNumber": 1290,
    "sessionIndex": 21,
    "validatorsLen": 1,
    "authorityIndex": 0
  },
  "signature": "0xcedf0727f483cbb8c642aabda9e69381c977771989e45ae8ae73b47fce63181068bba95cff8aedd76630670843748930fc0c4fa7307ad56fd4e25580f029ae8a"
}