{
  "manageEntity": {
    "action": "Save",
    "entityId": "1521620153",
    "entityType": "Track",
    "nonce": "1787954485381235561",
    "signature": "0x16da3e33b61dfd33569ee72f4608fefa30190de38fb81672f72aaa04bf60397c4a4e34927c350334075910c7fa0a38e3e3b94cc68cc0d49c6ef9aeccecdd1d261b",
    "signer": "0x512F9723ECbDB6Dc537A671b3D2fb35CC68017a4",
    "userId": "105562689"
  }
}