# File lib/xml/dom2/node.rb, line 491
      def trim(preserve = false)
        return nil if @children.nil?
        children = @children.to_a.dup
        children.each do |child|
          if !preserve && (child.nodeType == TEXT_NODE ||
                           child.nodeType == CDATA_SECTION_NODE)
            if child.trim == ""
              self.removeChild(child)
            end
          else
            child.trim(preserve)
          end
        end
        nil
      end