an><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='tstring'><span class='tstring_beg'>&#39;</span><span class='tstring_content'>invalid value for &quot;transaction_index&quot;, transaction_index cannot be nil.</span><span class='tstring_end'>&#39;</span></span><span class='