public void Transform()
 {
     Mock<IVirtualPathProvider> virtualPathProviderMock = new Mock<IVirtualPathProvider>();
     CssResourceImageUrlTransformer transformer = new CssResourceImageUrlTransformer(virtualPathProviderMock.Object);
     ResourceReadInfo result = transformer.Transform(new ResourceReadInfo
         {
             ResourceElement = new ResourceElement
                 {
                     FileName = "~/Content/css/site.css"
                 },
             ResourceInfo = new ResourceInfo
                 {
                     Content = "background-image:url(../images/x.jpg)"
                 }
         });
 }
 internal ResourceReadInfo TransformResource(ResourceType resourceType, ResourceReadInfo resource)
 {
     switch (resourceType)
     {
         case ResourceType.Js:
             break;
         case ResourceType.Css:
             resource = new CssResourceImageUrlTransformer(m_VirtualPathProvider).Transform(resource);
             break;
         default:
             throw new ResourceProcessorException("Unsupported resource type '{0}'".FormatWith(resourceType));
     }
     return resource;
 }