title: Why does dlib's neural net xml export contain different parameters for layers than specified by the trainer?
body: <p>In DLib it is possible to simply output a neural net type via the <code>dlib::net_to_xml(some_net, some_filename)</code> function. It works fine, but it also displays information like for example the net type, <code>learning_rate_multi</code>. In  my case for example it exports the following line for one of the layers (the rest of the exported xml is omitted for clarity):</p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;fc num_outputs='42' learning_rate_mult='1' weight_decay_mult='1' bias_learning_rate_mult='500' bias_weight_decay_mult='0'&gt;
  </code></pre>
  
  <p>Those values are correct, except for <code>learning_rate_mult</code> and <code>weight_decay_mult</code>, which always show 1. I tried setting them to different values with the trainer class, like 2 or 0.0001, but they keep showing 1. I verified that the values 2 and 0.0001 indeed were used by the net. </p>
  
  <p>Might this be a bug in dlib's <code>dlib::net_to:xml</code> function?</p>