{
  "manageEntity": {
    "action": "Save",
    "entityId": "666461773",
    "entityType": "Track",
    "nonce": "0x309987351c30603db1c7706223b507bb87d65b5486f2e73f46171831975a8007",
    "signature": "0x487bab232f0c32730883b03c605425f5625bd72b88fcccd56955921447e240964e510f76b34048b37626c184708aecac334e35257474000afc32ffcc6687d1661b",
    "signer": "0xE7D37531a757aEaf8B2c8037a79C03819edc20Dc",
    "userId": "870684573"
  }
}