{
  "manageEntity": {
    "action": "Save",
    "entityId": "1900528146",
    "entityType": "Track",
    "nonce": "0x150f251006745f11a3a8e5c5abe31ac39ab82c6534b4b3f86c442900192801a0",
    "signature": "0xe33f08f2235c50c8142d2dde51b5eb6f23d7b5b7e426056cda34f515903f96091560494981f72201ab8933c1b937c2e85800f83327f71c403cffcff74a62b15e1c",
    "signer": "0x84B42609E987DD0953e02498E61987fB833B7C92",
    "userId": "887547386"
  }
}