private async Task <Stream> GetTestReadStreamResult(DataServiceContext dataServiceContext, Document document) { dataServiceContext.Configurations.RequestPipeline.OnMessageCreating = args => { // if we read the wrong link then reply with gibberish var resp = (args.RequestUri == document.EntityDescriptor.ReadStreamUri) ? AttachmentResponse : "gibberish"; return(new CustomizedRequestMessage( args, resp, new Dictionary <string, string>() { { "Content-Type", "text/plain" }, })); }; var streamResponse = await dataServiceContext.GetReadStreamAsync(document, new DataServiceRequestArgs()); return(streamResponse.Stream); }