# File lib/qbxml/request.rb, line 21
    def <<(qbxml_request)
      if qbxml_request.is_a?(Qbxml::Request)
        set << qbxml_request
      elsif qbxml_request.respond_to?(:each)
        qbxml_request.each do |request|
          self << request
        end
      else
        raise ArgumentError, "Cannot add object of type #{qbxml_request.class.name} to a Qbxml::RequestSet"
      end
    end