title: Custom sheet with storyboard
body: <p>From 10.10 beginSheet:modalFor... to get a custom sheet is deprecated for beginSheet:completionHandler:
  So with storyboard I used only a NSViewController to "NSWindow" like customSheetView.view.window.
  This my code but nothing nothing is happening when I press my btn.</p>
  
  <pre><code>#import "vv.h"
  @property (strong) vv *customSheetView;
  
  @synthesize customSheetView;
  
  - (IBAction)displayCustomSheet:(id)sender {
  
  if (!customSheetView) {
      customSheetView = [[NSStoryboard storyboardWithName:@"Main" bundle:[NSBundle mainBundle]] instantiateControllerWithIdentifier:@"sheet"];
  }
  
  //[[NSApplication sharedApplication].windows objectAtIndex:0]
  [customSheetView.view.window beginSheet:self.view.window completionHandler:^(NSInteger result) {
                             switch (result) {
                                 case 0:
                                     self.outputLabel.stringValue = @"ok";
                                     break;
  
                                 case 1:
                                     self.outputLabel.stringValue = @"cancel";
                                     break;
  
                                 default:
                                     self.outputLabel.stringValue = @"You did something";
                                     break;
                             } 
                         }];   
  }
  </code></pre>