# File lib/xml/dom/core.rb, line 735
      def _preceding(reverse = false)
        return if @parent.nil?
        prev_sib = previousSibling
        if prev_sib
          prev_sib._preceding(reverse)   {|node| yield node} if reverse
          yield prev_sib
          prev_sib._descendant(!reverse) {|node| yield node}
          prev_sib._preceding(reverse)   {|node| yield node} if !reverse
        else
          @parent._preceding(reverse) {|node| yield node} if reverse
          yield @parent
          @parent._preceding(reverse) {|node| yield node} if !reverse
        end
      end