n_class</span>)
  <span class="ruby-keyword">if</span> <span class="ruby-identifier">exception_class</span> <span class="ruby-operator">!=</span> <span class="ruby-string">&quot;&quot;</span>
    <span class="ruby-identifier">save_exception_class_in_config_file</span>(<span class="ruby-identifier">app_name</span>,<span class="ruby-identifier">exception_class</span>)
  <span class="ruby-keyword">else</span>
    <span class="ruby-string">&quot;can't be blank.&quot;</span>
  <span class="ruby-keyword">end</spa