Extrinsic 8307-2

{
  "heartbeat": {
    "blockNumber": 8306,
    "sessionIndex": 138,
    "validatorsLen": 4,
    "authorityIndex": 1
  },
  "signature": "0xb8999ca9c6ac0bb32b4436fa84a7e5cd18e22068ee67900d9149b4472d7f447a598ef41fcae6f5d86eb9dc6e2149d853429da75793158e4c3d6ff22bec5cf987"
}