public void GivenAUserWhenAddsArticleThenTheArticleIsAdded()
{
// Arrange
var article = new Article();
article.Price = 95.5;
article.Name = "whatever";
PriceManager priceManager = new PriceManager();
// Act
priceManager.AddArticle(article);
// Assert
Assert.IsTrue(priceManager.Articles.Count == 1, "The article has not been properly added");
}