public void ContentIdMustBeDollarNumber()
        {
            IEdmEntityType type = ModelBuildingHelpers.BuildValidEntityType();
            Action         createWitnInvalidContentId1 = () => new BatchReferenceSegment("stuff", type, HardCodedTestModel.GetPeopleSet());
            Action         createWitnInvalidContentId2 = () => new BatchReferenceSegment("1$2", type, HardCodedTestModel.GetPeopleSet());
            Action         createWitnInvalidContentId3 = () => new BatchReferenceSegment("$", type, HardCodedTestModel.GetPeopleSet());
            Action         createWitnInvalidContentId4 = () => new BatchReferenceSegment("$0a1", type, HardCodedTestModel.GetPeopleSet());

            createWitnInvalidContentId1.ShouldThrow <ODataException>().WithMessage(ODataErrorStrings.BatchReferenceSegment_InvalidContentID("stuff"));
            createWitnInvalidContentId2.ShouldThrow <ODataException>().WithMessage(ODataErrorStrings.BatchReferenceSegment_InvalidContentID("1$2"));
            createWitnInvalidContentId3.ShouldThrow <ODataException>().WithMessage(ODataErrorStrings.BatchReferenceSegment_InvalidContentID("$"));
            createWitnInvalidContentId4.ShouldThrow <ODataException>().WithMessage(ODataErrorStrings.BatchReferenceSegment_InvalidContentID("$0a1"));
        }