/// <summary>
 /// Merge indexes using their path to identify them.
 /// Requires Solr 1.4+
 /// </summary>
 /// <param name="destinationCore"></param>
 /// <param name="indexDir"></param>
 /// <param name="indexDirs"></param>
 public ResponseHeader Merge(string destinationCore, MergeCommand.IndexDir indexDir, params MergeCommand.IndexDir[] indexDirs) {
     return SendAndParseHeader(new MergeCommand(destinationCore, indexDir, indexDirs));
 }
 /// <summary>
 /// Merge indexes using their core names to identify them.
 /// Requires Solr 3.3+
 /// </summary>
 /// <param name="destinationCore"></param>
 /// <param name="srcCore"></param>
 /// <param name="srcCores"></param>
 public ResponseHeader Merge(string destinationCore, MergeCommand.SrcCore srcCore, params MergeCommand.SrcCore[] srcCores) {
     return SendAndParseHeader(new MergeCommand(destinationCore, srcCore, srcCores));
 }