n><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;signing_payload&quot;, signing_payload 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'>@transaction_type</span><span class='period'>.</span><span class='id identifier rubyid_nil?'>nil?</spa