Dog.java

      public class Dog implements Animal {
    private String name;

    public Dog() {
    }

    public Dog(String name) {
        this.name = name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public String toString() {
        return name;
    }

    public void speak() {
        System.out.println("bow wow");
    }
}