private static string GetName(Expression expression)
        {
            var extractor = new NamesExtractor();

            extractor.Visit(expression);
            return(extractor.GetName());
        }
        static IEnumerable <IPersonReference> GetReferences(IPage page)
        {
            var names = new NamesExtractor(new NamesTokenizer()).ExtractNames(page.Text);

            return
                (from name in names
                 select new ConcreteExtractor.PersonReference()
            {
                Person = name.Person,
                Probability = name.Probability,
                Token = name.Token,
                Page = page
            });
        }