System.Text.RegularExpressions.Regex.ToString C# (CSharp) Метод

        public override string ToString()
        {
            throw null;
        }

 /// <summary>
 /// Constructor
 /// </summary>
 /// <param name="regex">Regular expression as Regex</param>
 /// <param name="errorMessage">Error message to show when validation fails</param>
 public RegularExpressionValidator(
     Regex regex,
     string errorMessage)
     : base(errorMessage)
 {
     Expression = regex.ToString();
     _regex = regex;
 }