title: How to allow last resnet block to be trainable?
body: <p>i want to make the last resnet block to be trainable, as i suspect that the features learned from ImageNet may not be directly relevant to my image classification problem.</p>
  
  <p>i managed to train vgg16 last block, and wonder how the same can be implemented also to resnet.</p>
  
  <pre><code>model.get_layer('block5_conv1').trainable = True
  model.get_layer('block5_conv2').trainable = True
  model.get_layer('block5_conv3').trainable = True
  model.get_layer('block5_pool').trainable = True
  </code></pre>