{
  "manageEntity": {
    "action": "Save",
    "entityId": "475448",
    "entityType": "Track",
    "nonce": "0x8151386d4625bda510c50edde0e628055eb3ba98ec96f3122ef1f7795439e0bd",
    "signature": "0x5c3069300e54a81f705965181e09a272606d6cbfc4df3b980a3eca6e3d71f0022d7989995354679e61558ea7e1f42d2241f7d0356c8c76cc1265c0d72cc2a4091c",
    "signer": "0x571CC6D512D6f6fe43A3EDFE62123a52785d36fA",
    "userId": "388520"
  }
}