ExampleClasses

using System;
​
namespace Simpsons
{
    public abstract class Pet
    {
        public abstract string? Name { get; set; }
​
        public override string? ToString()
        {
            return Name;
        }
    }
​
    public class Cat : Pet
    {
        public override string? Name { get; set; }
    }
​
    public class Dog : Pet
    {
        public override string? Name { get; set; }
    }
​
    public class Person
    {
        public Person()
        {
        }
​
        public Person(string name)
        {
            Name = name ?? throw new ArgumentNullException(nameof(name));
        }
​
        public string? Name { get; set; }
        public int Salary { get; set; }
​
        public override string? ToString()
        {
            return Name;
        }
    }
}