Extrinsic 18737-1

{
  "heartbeat": {
    "blockNumber": 18735,
    "sessionIndex": 312,
    "validatorsLen": 4,
    "authorityIndex": 2
  },
  "signature": "0x42ad26421ebc63a4935d29f8f3f8e7cf58f25c62cb56aa2cd706038bd8fe44190fd252b02b888c2cab35030a6965a20e1caecd975f58fb521d86c91416bc2088"
}