/// <summary>
 /// Initializes a new instance of the <see cref="TopicKeywordExtractor"/> class.
 /// </summary>
 /// <param name="filter">The filter<see cref="NRakeCore.StopWordFilters.IStopWordFilter"/></param>
 public TopicKeywordExtractor(NRakeCore.StopWordFilters.IStopWordFilter filter) : this()
 {
     KeywordExtractor = new NRakeCore.KeywordExtractor(filter);
 }
 /// <summary>
 /// Initializes a new instance of the <see cref="Phrase"/> class.
 /// </summary>
 /// <param name="keyword">The keyword<see cref="string"/></param>
 /// <param name="aggregatedLeagueTable">The aggregatedLeagueTable<see cref="SortedList{string, double}"/></param>
 /// <param name="topics">The topics<see cref="Topics"/></param>
 /// <param name="stopFilter">The stopFilter<see cref="NRakeCore.StopWordFilters.IStopWordFilter"/></param>
 /// <param name="rank">The rank<see cref="int"/></param>
 public Phrase(string keyword, SortedList <string, double> aggregatedLeagueTable, Topics topics, NRakeCore.StopWordFilters.IStopWordFilter stopFilter, int rank) : this(keyword, aggregatedLeagueTable, rank)
 {
     Topics.AddRange(topics.Where(topic => TopicKeywords(topic, stopFilter).Contains(keyword)).ToArray());
 }
 /// <summary>
 /// Initializes a new instance of the <see cref="TopicKeywordExtractor"/> class.
 /// </summary>
 /// <param name="topics">The topics<see cref="List{Topic}"/></param>
 /// <param name="filter">The filter<see cref="NRakeCore.StopWordFilters.IStopWordFilter"/></param>
 public TopicKeywordExtractor(List <Topic> topics, NRakeCore.StopWordFilters.IStopWordFilter filter) : this(topics)
 {
     KeywordExtractor = new NRakeCore.KeywordExtractor(filter);
 }
        /// <summary>
        /// The TopicKeywords
        /// </summary>
        /// <param name="topic">The topic<see cref="Topic"/></param>
        /// <param name="stopFilter">The stopFilter<see cref="NRakeCore.StopWordFilters.IStopWordFilter"/></param>
        /// <returns>The <see cref="string[]"/></returns>
        private string[] TopicKeywords(Topic topic, NRakeCore.StopWordFilters.IStopWordFilter stopFilter)
        {
            var tke = new KeywordExtractor(stopFilter);

            return(tke.FindKeyPhrases(topic.GetText()));
        }