private Either <string, int> Validate(GetIngredientById query) => GreatThanZero(query.Id) .ToEither("O id de para pequisa tem que ser maior que 0");
public Task <Either <string, Ingredient> > Handle(GetIngredientById query) => Validate(query) .Match( id => RetrieveIngredient(id), e => Task.FromResult(new Either <string, Ingredient>(e)) );