title: RestKit mapping multiple type array
body: <p>I have following JSON:</p>
  
  <pre><code>{
      "stream": [{
          "catalog": {}
      }, {
          "catalog": {}
      }, {
          "user": {}
      }]
  }
  </code></pre>
  
  <p>with following mapping rules:</p>
  
  <pre><code>[RKResponseDescriptor responseDescriptorWithMapping:catalogMapping
                                          pathPattern:nil keyPath:@"stream.catalog"
                                          statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)]];
  
  [RKResponseDescriptor responseDescriptorWithMapping:userMapping
                                          pathPattern:nil keyPath:@"stream.user"
                                          statusCodes:RKStatusCodeIndexSetForClass(RKStatusCodeClassSuccessful)]];
  </code></pre>
  
  <p>Mapping works fine until multiple type of object are in the stream. When stream contain multiple objects, say user and catalog restkit fails this assert:</p>
  
  <pre><code>NSCAssert([representation isKindOfClass:[NSDictionary class]], @"Expected a dictionary representation");
  </code></pre>
  
  <p>Is there a way map that structure?</p>