title: How can I update the attributeMappings for RKObjectMapping
body: <p>Because I have the Core Data objects same as the domain objects coming from the server I am using the following code to automatically setup the mapping:</p>
  
  <pre><code>RKObjectMapping *mapping = [RKEntityMapping mappingForEntityForName:entityClassName inManagedObjectStore:managedObjectStore];
  
  // Get the list of attributes
  NSEntityDescription* entityInfo = [NSEntityDescription entityForName:entityClassName inManagedObjectContext:managedObjectContext];
  
  [mapping addAttributeMappingsFromArray:[[entityInfo attributesByName] allKeys]];
  </code></pre>
  
  <p>Later, because there is one attribute which is specific I need to update the     mapping.attributeMappings array. But I can not remove/clear the old array as it is read only. Is there any official way how to update the array?</p>