/// <summary>
 /// Search web infos.
 /// </summary>
 /// <param name="keyword">The keyword.</param>
 /// <param name="resultCount">The count of result itmes.</param>
 /// <param name="language">The language you want to search.</param>
 /// <param name="safeLevel">The search safety level.</param>
 /// <returns>The result itmes.</returns>
 /// <remarks>Now, the max count of items Google given is <b>64</b>.</remarks>
 public IList <IWebResult> Search(string keyword, int resultCount, string language, string safeLevel)
 {
     return(this.Search(keyword, resultCount, null, null, safeLevel, language, DuplicateFilter.GetDefault(), null));
 }
 /// <summary>
 /// Begins an asynchronous request for searching web infos.
 /// </summary>
 /// <param name="keyword">The keyword.</param>
 /// <param name="resultCount">The count of result itmes.</param>
 /// <param name="language">The language you want to search.</param>
 /// <param name="safeLevel">The search safety level.</param>
 /// <param name="callback">The <see cref="AsyncCallback"/> delegate.</param>
 /// <param name="state">An object containing state information for this asynchronous request.</param>
 /// <returns>An <see cref="IAsyncResult"/> that references the asynchronous request.</returns>
 public IAsyncResult BeginSearch(string keyword, int resultCount, string language, string safeLevel, AsyncCallback callback, object state)
 {
     return(this.BeginSearch(keyword, resultCount, null, null, safeLevel, language, DuplicateFilter.GetDefault(), null, callback, state));
 }