{
  "manageEntity": {
    "action": "Save",
    "entityId": "547054",
    "entityType": "Track",
    "metadata": "{\"is_save_of_repost\":false}",
    "nonce": "1788185023675550273",
    "signature": "0xbc9b282bf4a1aca799f414710fa704fc077867a087e95f978a0e86f9b923b79317b40ea6b8aac5ba376124795d7b77d856197c7991aab3d0ce9f398e35be46a81c",
    "signer": "0x922cb2AE695da9f7Dd0e556954c23eeeb8bfFe0E",
    "userId": "662047520"
  }
}