這樣寫的確是實現了多態，但Dog和Cat并沒有顯式實現Behavior這個接口，而編譯器就已經將其做了關聯。為什么不需要像Java一樣的implements 顯式實現接口？

func?main()?{
???dog?:=?Dog{Name:?"wangwang",?Age:?2}
???cat?:=?Cat{Name:?"mimi",?Age:?2}
???fmt.Println(dog.Eat())
???fmt.Println(dog.Run())
???fmt.Println(cat.Eat())
???fmt.Println(cat.Run())
}

type?Animal?struct?{
???Kind?string
}

type?Cat?struct?{
???Animal
???Name?string
???Age?int
}

func?(cat?*Cat)?Eat()?string?{
???return?"cat:?eat"
}

func?(cat?*Cat)?Run()?string?{
???return?"cat:?run"
}

type?Dog?struct?{
???Animal
???Name?string
???Age?int
}

func?(dog?*Dog)?Eat()?string?{
???return?"dog:?eat"
}

func?(cat?*Dog)?Run()?string?{
???return?"dog:?run"
}


type?Behavior?interface?{
???Eat()?string
???Run()?string
}