file/received/get - Returns a single existing received file.id - The ID of the received file to get.{id: <number> - The ID of the received file.sender_username: <string> - The username of who sent the file.name: <string> - The name of the received file.size: <number> - The size of the content of the received file in bytes.md5_sum: <string> - The MD5 hash of the content of the file.sha256_sum: <string> - The SHA-256 hash of the content of the file.insert_time: <number> - The Unix timestamp of when the file was received.}RECEIVED_FILE_NOT_FOUND - A received file with the ID doesn't exist.