# File lib/asciidoctor/converter/html5.rb, line 634
    def stem node
      id_attribute = node.id ? %( id="#{node.id}") : nil
      title_element = node.title? ? %(<div class="title">#{node.title}</div>\n) : nil
      open, close = BLOCK_MATH_DELIMITERS[node.style.to_sym]

      unless ((equation = node.content).start_with? open) && (equation.end_with? close)
        equation = %(#{open}#{equation}#{close})
      end

      %(<div#{id_attribute} class="stemblock#{(role = node.role) && " #{role}"}">
#{title_element}<div class="content">
#{equation}
</div>
</div>)
    end