C#

private string ComputeMD5(string value)
{
  MD5 md5 = new MD5CryptoServiceProvider();
  byte[] buffer = Encoding.UTF8.GetBytes(value);
  byte[] cipher = md5.ComputeHash(buffer);
  StringBuilder sb = new StringBuilder(cipher.Length * 2);
  for (int i=0; i<cipher.Length; i++)
    sb.Append(cipher[i].ToString("x2"));
  return sb.ToString();
}

public sealed class Options
{
  private Options() {} // Prevent instantiation
  private static int option1;
  private static string option2;
  public static int Option1
  {
    get { return option1; }
    set
    {
      if (value < 0) throw new ArgumentException();
      option1 = value;
    }
  }
  public static string Option2
  {
    get { return option2; }
    set
    {
      if (value == null) throw new ArgumentNullException();
      option2 = value;
    }
  }
}

string option1 = Options.Option2;
Options.Option1 = 10;

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