an> <span class='kw'>if</span> <span class='ivar'>@colours</span><span class='period'>.</span><span class='id identifier rubyid_index'>index</span><span class='lparen'>(</span><span class='id identifier rubyid_colour'>colour</span><span class='rparen'>)</span><span class='period'>.</span><span class='id identifier rubyid_nil?'>nil?</span>
   <span class='kw'>end</span>
   <span class='kw'>self</span>
<span class='kw'>end</span></pre>
    </td>
  </tr>
</table>
</div>
    
      <div class="method_details