docs: def get_html_column(self):
          """ Get a HTML column for this panel. """
  
          panel_id = "panel_{}".format(self.name)
          return ["<h2>{}</h2>".format(self.title) + '<a href="{}">Download data</a>'.format(self.tar_fn())] + [
              # list of links
              (" <br />" + os.linesep).join(
                  [
                      """
  						   <strong>{bam_name}:</strong>
  						   <a onclick="document.getElementById('{panel_id}').src='{bam_svg}';document.getElementById('{panel_id}_').href='{bam_html}';return false;" href="#">display graph</a>,
  						   <a href="{bam_html}">detailed report</a>
  						   """.format(
                          bam_name=bam.get_name(),
                          bam_html=bam.html_fn(),
                          bam_svg=bam.svg_fn(),
                          panel_id=panel_id,
                      ) for bam in self.bams
                  ]
              ) + '<br /> '.format(self.tar_fn()),
  
              # main graph
              """
  				   <div class="formats">
  				   <a href="{html}" id="{panel_id}_">
  				   <img src="{svg}" id="{panel_id}" />
  				   </a>
  				   </div>
  				   """.format(
                  html=self.bams[0]._html_fn,
                  svg=self.bams[0]._svg_fn,
                  panel_id=panel_id,
              ),
          ] + [
              # overall graphs
              """
  				   <div class="formats">
  				   <img src="{svg}" />
  				   <br />
  				   <a href="{svg}">SVG version</a>
  				   |
  				   <a href="{gp}" type="text/plain">GP file</a>
  				   </div>
  				   
  				   """.format(
                  svg=svg,
                  gp=self._gp_fn,
              ) for svg in self._svg_fns
          ]