IOS 11 Drag'n'Drop How to drop custom file

I need to copy dropped data to my custom path. With images it's working fine. Here is the code:

- (UIDropProposal *)dropInteraction:(UIDropInteraction *)interaction sessionDidUpdate:(id<UIDropSession>)session {
    UIDropProposal *proposal = [[UIDropProposal alloc] initWithDropOperation: UIDropOperationCopy];
return proposal;
 }

- (BOOL)dropInteraction:(UIDropInteraction *)interaction canHandleSession:(id<UIDropSession>)session {
  return [session canLoadObjectsOfClass:[UIImage self]];
 }

 - (void)dropInteraction:(UIDropInteraction *)interaction performDrop:(id<UIDropSession>)session {

[session loadObjectsOfClass:[UIImage self] completion:^(NSArray *images) {

    UIImage *image=(UIImage*)[images objectAtIndex:0];


    [UIImagePNGRepresentation(image) writeToFile:"<MYPATH>" atomically:YES];

}];

}

This code nicely save dropped image to MYPATH... But what, if i want to save non-image file, but some custom format "mybinarydata.dat"? I understand that I must use loadObjectsOfClass:[NSData self] and save "objectAtIndex:0" directly? - but i's now working(((