addTarget:action:forControlEvents: from a UITableViewCell
<p>I have a UITableViewCell with 3 checkmark buttons.  Each checkmark button is a custom UIButton (just the images really), and have an outlet in the custom UITableViewCell subclass.  In the cellForRowAtIndexPath method, I</p>

<pre><code>[cell.firstcheckmark addTarget:self action:@selector(checkmarkPressed:) forControlEvents:UIControlEventTouchUpInside];
[cell.secondcheckmark addTarget:self action:@selector(checkmarkPressed:) forControlEvents:UIControlEventTouchUpInside];
[cell.thirdcheckmark addTarget:self action:@selector(checkmarkPressed:) forControlEvents:UIControlEventTouchUpInside];

- (void)checkmarkPressed:(id)sender {
   // how do I get which checkmark was pressed?
}
</code></pre>

<p>I was not sure how to get which button was pressed from the sender object.  Other times I can use the title of the button, but in this case, all the buttons are the same except their outlet.  How do I get which button was pressed?  Or do they each need to call a different method, and then in each of those three methods, I can update my model by calling the same modelUpdateMethod: from each of those three methods?  Thanks.</p>
