using static System.Console;

public class Program

{

    public static void Main()

    {

        var testeName = GetCustomAttribute()?.DisplayName;

        WriteLine(testeName ?? "Null");

    }

    public static CustomAttr GetCustomAttribute()

    {

        return null;

    }

}

​

public class CustomAttr

{

    public string Name;

    public string DisplayName;

}