title: use TCPDF in threads that created with pthreads
body: <p>I want use<code>TCPDF</code> in threads that created with <code>pthreads</code> in <code>php</code>.<br>
  When i use <code>TCPDF</code> this <strong>error appears:</strong>  </p>
  
  <blockquote>
    <p>"Notice: Undefined variable: _SERVER in ..."</p>
  </blockquote>
  
  <p>how i must resolve it?  </p>