How to create a custom cell type?

I would like to use this library in combination with prawn-html, but I am unsure how to render HTML into a table cell.

My current approach is to create a custom cell class:

class HtmlCell < Prawn::Table::Cell
  def draw_content
    PrawnHtml.append_html(self, content)
  end
end

and use it as such:

class PrintView
  include Prawn::View

  def print_section_x
    table [["header"], [HtmlCell.make(self, "<p>Test</p>")]]
  end
end

but unfortunately the draw_content method is never called. The code clearly states that the Cell type can be extended:

but I can't find any examples. Is this currently possible?

prawnpdf / prawn-table