/// <summary>
 ///     Adds a keyword to the source-list.
 /// </summary>
 /// <param name="keyword">The keyword.</param>
 public void AddKeyword(SourceListKeyword keyword)
 {
     ThrowIfNoneIsSet();
     if (mKeywords.Contains(keyword)) {
         return;
     }
     mKeywords.Add(keyword);
 }
 /// <summary>
 ///     Adds a keyword to the source-list.
 /// </summary>
 /// <param name="keyword">The keyword.</param>
 public void AddKeyword(SourceListKeyword keyword)
 {
     ThrowIfNoneIsSet();
     if (mKeywords.Contains(keyword))
     {
         return;
     }
     mKeywords.Add(keyword);
 }