# File lib/asciidoctor/backends/base_template.rb, line 99
  def attrvalue(key, sibling = true, inherit = true)
    delimiter = sibling ? ' ' : ''
    if inherit
      # example: <% if attr? 'foo' %><%= attr 'foo' %><% end %>
      %(<% if attr? '#{key}' %>#{delimiter}<%= attr '#{key}' %><% end %>)
    else
      # example: <% if attr? 'foo', nil, false %><%= attr 'foo', nil, false %><% end %>
      %(<% if attr? '#{key}', nil, false %>#{delimiter}<%= attr '#{key}', nil, false %><% end %>)
    end
  end