using System;
using System.Linq;
#nullable enable
public class Program
{
	public class MyClass : IEquatable<MyClass>
	{
		private object property;
		public MyClass()
		{
			property = 1;
		}
		public bool Equals(MyClass? other)
		{
			Console.WriteLine("MyClass? called");
			if (ReferenceEquals(null, other))
			{
				return true;
			}
			return Equals(property, other.property);
		}
		public override bool Equals(object? obj)
		{
			Console.WriteLine("object? called");
			if (ReferenceEquals(null, obj))
			{
				return false;
			}
			if (ReferenceEquals(this, obj))
			{
				return true;
			}
			if (obj.GetType() != GetType())
			{
				return false;
			}
			return Equals((MyClass)obj);
		}
		public override int GetHashCode()
		{
			return HashCode.Combine(property);
		}
	}
	public static void Main()
	{
		var a = new MyClass();
		var b = new MyClass();
		Console.WriteLine(a.Equals(b)); // Equals(MyClass? other)
		Console.WriteLine(Equals(a, b)); // Equals(object? obj)
		Console.WriteLine(IEquatable<MyClass>.Equals(a, b)); // Equals(object? obj)
	}
}