protected virtual void IndexItemCustomProperties(ref ResultDocument doc, CatalogProduct item)
        {
            var properties = item.CategoryId != null ? _propertyService.GetCategoryProperties(item.CategoryId) : _propertyService.GetCatalogProperties(item.CatalogId);

            foreach (var propValue in item.PropertyValues.Where(x => x.Value != null))
            {
                var property = properties.FirstOrDefault(x => string.Equals(x.Name, propValue.PropertyName, StringComparison.InvariantCultureIgnoreCase) && x.ValueType == propValue.ValueType);
                var contentField = string.Format("__content{0}", property != null && (property.Multilanguage && !string.IsNullOrWhiteSpace(propValue.LanguageCode)) ? "_" + propValue.LanguageCode.ToLower() : string.Empty);

                switch (propValue.ValueType)
                {
                    case PropertyValueType.LongText:
                    case PropertyValueType.ShortText:
                        var stringValue = propValue.Value.ToString();

                        if (!string.IsNullOrWhiteSpace(stringValue)) // don't index empty values
                        {
                            doc.Add(new DocumentField(contentField, stringValue.ToLower(), new[] { IndexStore.Yes, IndexType.Analyzed, IndexDataType.StringCollection }));
                        }

                        break;
                }

                if (doc.ContainsKey(propValue.PropertyName))
                    continue;


                switch (propValue.ValueType)
                {
                    case PropertyValueType.Boolean:
                    case PropertyValueType.DateTime:
                    case PropertyValueType.Number:
                        doc.Add(new DocumentField(propValue.PropertyName, propValue.Value, new[] { IndexStore.Yes, IndexType.Analyzed }));
                        break;
                    case PropertyValueType.LongText:
                    case PropertyValueType.ShortText:
                        doc.Add(new DocumentField(propValue.PropertyName, propValue.Value.ToString().ToLower(), new[] { IndexStore.Yes, IndexType.Analyzed }));
                        break;
                }
            }
        }
        /// <summary>
        /// Creates result document collection from Lucene documents.
        /// </summary>
        /// <param name="searcher">The searcher.</param>
        /// <param name="topDocs">The hits.</param>
        private void CreateDocuments(Searcher searcher, TopDocs topDocs)
        {
            // if no documents found return
            if (topDocs == null)
                return;

            var entries = new List<ResultDocument>();

            // get total hits
            var totalCount = topDocs.TotalHits;
            var recordsToRetrieve = Results.SearchCriteria.RecordsToRetrieve;
            var startIndex = Results.SearchCriteria.StartingRecord;
            if (recordsToRetrieve > totalCount)
                recordsToRetrieve = totalCount;

            for (var index = startIndex; index < startIndex + recordsToRetrieve; index++)
            {
                if (index >= totalCount)
                    break;

                var document = searcher.Doc(topDocs.ScoreDocs[index].Doc);
                var doc = new ResultDocument();

                var documentFields = document.GetFields();
                using (var fi = documentFields.GetEnumerator())
                {
                    while (fi.MoveNext())
                    {
                        if (fi.Current != null)
                        {
                            var field = fi.Current;

                            // make sure document field doens't exist, if it does, simply add another value
                            if (doc.ContainsKey(field.Name))
                            {
                                var existingField = doc[field.Name] as DocumentField;
                                if (existingField != null)
                                    existingField.AddValue(field.StringValue);
                            }
                            else // add new
                            {
                                doc.Add(new DocumentField(field.Name, field.StringValue));
                            }
                        }
                    }
                }

                entries.Add(doc);
            }

            var searchDocuments = new ResultDocumentSet
            {
                Name = "Items",
                Documents = entries.ToArray(),
                TotalCount = totalCount
            };

            Results.Documents = new[] { searchDocuments };
        }