title: what's the value of drop_path_keep_prob used for Auto DeepLab
body: <p>The default <code>drop_path_keep_prob</code> is 1.0 defined <a href="https://github.com/tensorflow/models/blob/master/research/deeplab/train.py#L147" rel="nofollow noreferrer">here</a>.
  But the <code>Drop Path</code> doesn't contribute anything if the <code>drop_path_keep_prob</code> is not less than 1.0.</p>
  <p>What's the exact value used for training the Auto DeepLab?</p>