public async Task Post_with_multiple_attachment() { var mutation = @"mutation { withAttachment (argument: ""argumentValue"") { argument } }"; using var content = new MultipartFormDataContent(); content.AddQueryAndVariables(mutation); content.AddContent("key1", "foo1"); content.AddContent("key2", "foo2"); using var response = await client.PostAsync("graphql", content); await Verify(response.ProcessResponse()); }