class="ruby-identifier">key</span>] = <span class="ruby-identifier">value</span>[<span class="ruby-value">0</span>]
    <span class="ruby-identifier">current_values</span>[<span class="ruby-identifier">key</span>] = <span class="ruby-identifier">value</span>[<span class="ruby-value">1</span>]
  <span class="ruby-keyword">end</span>
  [<span class="ruby-identifier">previous_values</span>, <span class="ruby-identifier">current_values</span>]
<span class="ruby-keyword">end</span></pre>
          </div>
       