public class Program {
	public static void Main() {
		var dog = new Cachorro() { Nome = "Toy", Patas = 4, MesesGestacao = 3, Especie = "Cachorro" };
		IPet<Animal> p1 = new Pet<Cachorro>();
	}
}
class Animal {
	public string Especie { get; set; }
}
class Mamifero : Animal {
	public int MesesGestacao { get; set; }
}
class Cachorro : Mamifero {
	public string Nome { get; set; }
	public int Patas { get; set; }
}
interface IPet<out T> where T : Animal {
	string Apelido { get; set; }
}
class Pet<T> : IPet<T> where T : Animal {
	public string Apelido { get; set; }
}
 
//https://pt.stackoverflow.com/q/508268/101

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