RegularExpressionMultiMatchAttribute that allows multiple matches for data annotations (ex. w/ ASP.NET MVC)

RegularExpressionMultiMatchAttribute.cs

public class RegularExpressionMultiMatchAttribute : RegularExpressionAttribute
{
    public RegularExpressionMultiMatchAttribute(string pattern)
        : base(pattern)
    {

    }

    public override bool IsValid(object value)
    {
        var regex = new Regex(Pattern);
        
        Match match;

        if (value != null)
        {
            match = regex.Match(value.ToString());
        }
        else
        {
            match = regex.Match("");
        }

        return match.Success;
    }
}