let recipeBook = (function () {
    class recipeBook{
        constructor(recipes){
            this._recipes = recipes || [];
        }
        addRecipe(recipe){
            this._recipes.push(recipe);
        }
        removeRecipe(id){
            this._recipes.splice(id, 1);
        }
        getRecipes(){
            return this._recipes;
        }
    }
	return recipeBook;
})();