title: Write html to custom header tcpdf
body: <p>I'm struggling to understand how the header function is working in tcpdf.</p>
  
  <p>Is is possible to use $pdf->writeHTML to the header?</p>
  
  <p><a href="http://www.tcpdf.org/examples/example_003.phps" rel="noreferrer">http://www.tcpdf.org/examples/example_003.phps</a></p>
  
  <p>I would like to display 3 columns in the header.</p>
  
  <pre><code> Column1 Column2 Column3
  </code></pre>