/// <summary>
        /// Get all index alias.
        /// </summary>
        /// <returns>All index alias.</returns>
        public Dictionary <String, String> GetIndexAliases()
        {
            Dictionary <String, String>             aliases;
            ElasticsearchResponse <DynamicResponse> response;
            Int32  index;
            String indexAliases, indexName;

            response = _client.IndicesGetAliasesForAll <DynamicResponse>();
            CheckResponse(response);
            aliases = new Dictionary <String, String>();
            if (response.Body.Keys.IsNotNull() && (response.Body.Keys.Count > 0))
            {
                for (index = 0; index < response.Body.Keys.Count; index++)
                {
                    indexName    = response.Body.Keys.ElementAt(index);
                    indexAliases = response.Body.Values.ElementAt(index);
                    Debug.WriteLine("Index name = " +
                                    indexName +
                                    ", aliases = " + indexAliases);
                    aliases[indexName] = indexAliases;
                }
            }

            return(aliases);
        }