{
  "manageEntity": {
    "action": "Save",
    "entityId": "664719",
    "entityType": "Track",
    "nonce": "0x442879370fdb8726b3e9586c3b997e7f0ef6ed08f00f3fe5284bc9a38b16006a",
    "signature": "0x9a1457fe3eb9a38dbdb86d9366834855bd17f0cc7ecd4b08e0658cdd7190efa01834a6a308c9833ed37091265509381a634b39f9e924dba79af05695e887f2601c",
    "signer": "0x243A439c272133AEEE0073AF4986dE391C430866",
    "userId": "77551267"
  }
}