Question: my application just get the text from the clipboard and set it into a listbox
and I need to save the items of listbox for next lunch
I've used this code for that

```
StreamWriter SaveFile = new StreamWriter(sPath);
numlastline = listBox1.Items.Count-1;
SaveFile.WriteLine(listBox1.Items[numlastline]);
SaveFile.ToString();
SaveFile.Close();

```

but its only save the last clip to the text and delet the Previous ones

Answer: 
The error says that `downloadURL` has no return value. It uses a completion handler to return data from an asynchronous task

I'm not familiar with Firebase but the syntax of the API seems to be

```
metadata?.storageReference?.downloadURL( completion: { (url, error) in
    let changeRequestPhoto = user?.user.createProfileChangeRequest()
    changeRequestPhoto?.photoURL = url
    changeRequestPhoto?.commitChanges(completion: { error in
        if let error = error {
            print (error.localizedDescription)
            return
        }
        else {
            print ("Sweet!")
        }
    })
})

```
You need to add proper completion handling for the first row

```
self.fileURL = metadata?.storageReference?.downloadURL(completion: { (url, error) in
    if (error == nil) {
       //do something with the url
    } else {
      // error handling
    }
 })

```