title: Create subclass with different subclass property
body: <p>Say I have this Class</p>
  
  <pre><code>@interface CustomClass : NSObject
  
  @property (nonatomic, strong) NSArray * nicestArrayEver;
  
  @end
  </code></pre>
  
  <p>And I want to create a subClass of CustomClass, but here is the catch</p>
  
  <pre><code>@interface ASubClassCustomClass : CustomClass
  
  @property (nonatomic, strong) NSMutableArray * nicestArrayEver;
  
  @end
  </code></pre>
  
  <p>The issue as you can imagine is that when I initialize ASubClassCustomClass and call it's super initializer (since there is other properties required) the inmutable nicestArrayEver is created.. how can I avoid it's creation so I can set the mutable one?</p>
  
  <p>Note: This is just an example, the real implementation calls a heavy to create and really customized subclass (is not an NSArray). </p>