create a FTPClient class that can use for FTP operations

public class FTPClient {
  public FTPClient() {
    System.out.println("this is the constructor of FTPClient");
  }
  
  public void download(String file) {
    System.out.println("downloading file: " + file);
  }
}

FTPClient client = new FTPClient();
client.download("test.txt");