value for &quot;index&quot;, index cannot be nil.</span><span class='tstring_end'>&#39;</span></span><span class='rparen'>)</span>
  <span class='kw'>end</span>

  <span class='kw'>if</span> <span class='ivar'>@public_key</span><span class='period'>.</span><span class='id identifier rubyid_nil?'>nil?</span>
    <span class='id identifier rubyid_invalid_properties'>invalid_properties</span><span class='period'>.</span><span class='id identifier rubyid_push'>push</span><span class='lparen'>(</span><span class