Extrinsic 18753-1

{
  "heartbeat": {
    "blockNumber": 18752,
    "sessionIndex": 312,
    "validatorsLen": 4,
    "authorityIndex": 3
  },
  "signature": "0xd008ddc467f89094238586208867b7fdd94b79460b42cbe8e5e5956d26e82e57489a463ea7c71699bdcdb163e96ce693233a82d292159b4058956f6bf9e13b83"
}