C# 9 supports which framworks code example

Example 1: c# record

public sealed record Student : Person
{
    public int Level { get; }

    public Student(string first, string last, int level) : base(first, last) => Level = level;
}

Example 2: c# record

public record Person
{
    public string LastName { get; }
    public string FirstName { get; }

    public Person(string first, string last) => (FirstName, LastName) = (first, last);
}