public IEnumerable<CharacterRange> FindAllMatchedRanges(string cellText) {
List<CharacterRange> ranges = new List<CharacterRange>();
foreach (TextMatchingStrategy filter in this.MatchingStrategies) {
if (!String.IsNullOrEmpty(filter.Text))
ranges.AddRange(filter.FindAllMatchedRanges(cellText));
}
return ranges;
}