def get_node_content(args)
      return nil if block_given?
      content = nil
      args.each do |arg|
        case arg
          when Hash
            next
          when Time
            # eBay official TimeStamp format YYYY-MM-DDTHH:MM:SS.SSSZ
            content = arg.strftime('%Y-%m-%dT%H:%M:%S.%Z')
          when DateTime
            content = arg.strftime('%Y-%m-%dT%H:%M:%S.%Z')
            break
          else
            content = arg.to_s
            break
        end
      end
      content
    end
def get_node_content(args)
      return nil if block_given?
      content = nil
      args.each do |arg|
        case arg
          when Hash
            next
          when Time
            # eBay official TimeStamp format YYYY-MM-DDTHH:MM:SS.SSSZ
            content = arg.strftime('%Y-%m-%dT%H:%M:%S.%Z')
          when DateTime
            content = arg.strftime('%Y-%m-%dT%H:%M:%S.%Z')
            break
          else
            content = arg.to_s
            break
        end
      end
      content
    end
Return the node content as a String, unless a block is given.
 @return [String] the node data.