# File rexml/document.rb, line 90
    def add( child )
      if child.kind_of? XMLDecl
	@children.unshift child
      elsif child.kind_of? DocType
	if @children[0].kind_of? XMLDecl
	  @children[1,0] = child
	else
	  @children.unshift child
	end
      else
	rv = super
	raise "attempted adding second root element to document" if @elements.size > 1
	rv
      end
    end