Extrinsic 2976-2

{
  "heartbeat": {
    "blockNumber": 2974,
    "sessionIndex": 49,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0x643e16d55a748af173a9b8c7a39180738b94c3f6edd61b937735f63aa0f43052c915fadba5d234e98a0698460d732a28699b0ed78fcbd1ae6abd613ab928138e"
}