title: UI_APPEARANCE_SELECTOR required or not?
body: <p>For below code to work we should generally define a aFont property in TestView.h with UI_APPEARANCE_SELECTOR. But, it seems it is not required. I tried with and without the UI_APPEARANCE_SELECTOR, results are the same. </p>
  
  <p>I don't know if this is right or wrong?</p>
  
  <blockquote>
    <p>[[TestView appearance] setAFont:[UIFont boldSystemFontOfSize:20.0f]]; </p>
  </blockquote>
  
  <pre><code>#import "ViewController.h"
  #import "TestView.h"
  @interface ViewController ()
  
  @end
  
  @implementation ViewController
  
  - (void)viewDidLoad {
      [super viewDidLoad];
      // Do any additional setup after loading the view, typically from a nib.
       [[TestView appearance] setAFont:[UIFont boldSystemFontOfSize:20.0f]];
  }
  
  -(void)viewWillAppear:(BOOL)animated{
      [super viewWillAppear:animated];
  
  }
  
  - (void)didReceiveMemoryWarning {
      [super didReceiveMemoryWarning];
      // Dispose of any resources that can be recreated.
  }
  
  @end
  </code></pre>
  
  <p><strong>TestView.h</strong></p>
  
  <pre><code>#import &lt;UIKit/UIKit.h&gt;
  
  @interface TestView : UIView
  @property (strong,nonatomic) UIFont *aFont  ;
  @end
  </code></pre>
  
  <p><strong>TestView.m</strong></p>
  
  <pre><code>#import "TestView.h"
  
  @implementation TestView
  {
      UILabel *aTestLabel;
  }
  @synthesize aFont=_aFont;
  
  - (void)drawRect:(CGRect)rect {
      // Drawing code
      NSLog(@"A Font= %@ ",_aFont);
  }
  
  
  -(id) init{
      self=[super init];
      if(self){
          [self addLabel];
      }
      return self;
  }
  
  -(id) initWithCoder:(NSCoder *)aDecoder{
      self=[super initWithCoder:aDecoder];
      if(self){
          [self addLabel];
      }
      return self;
  }
  
  -(void)addLabel{
      aTestLabel=[[UILabel alloc] initWithFrame:self.bounds];
      aTestLabel.text=@"Hello";
      _aFont=[UIFont systemFontOfSize:10.0];
  
      [self addSubview:aTestLabel];
  }
  
  -(void)setAFont:(UIFont *)aFont{
      _aFont=aFont;
      aTestLabel.font=_aFont;    
  }
  </code></pre>