# File lib/rspec/mocks/message_expectation.rb, line 472
      def call(&block)
        default_return_value = perform_yield(&block)
        return default_return_value unless @values_to_return

        if @values_to_return.size > 1
          @values_to_return.shift
        else
          @values_to_return.first
        end
      end