# File lib/moqueue/matchers.rb, line 10
      def matches?(queue)
        if queue.respond_to?(:received_message?)
          @queue = queue
          @queue.received_message?(@expected_msg)
        else
          raise NoMethodError, 
          "Grrr. you can't use ``should have_received_message'' on #{queue.inspect} " +
          "because it doesn't respond_to :received_message?"
        end
      end