namespace System
{
    [DefaultMember("Chars")]
    public sealed class String : IEnumerable, IEnumerable<char>, ICloneable, IComparable, IComparable<string?>, IConvertible, IEquatable<string?>
    {
        [EditorBrowsable(EditorBrowsableState.Never)]
        [Obsolete("This API should not be used to create mutable strings. See https://go.microsoft.com/fwlink/?linkid=2084035 for alternatives.")]
        public static string! Copy(string! str);
    }
}