public Index getIndex(String indexName) {
            return IndexFacts.this.getIndexFromDocumentTypes(indexName, documentTypes);
        }
Returns the index for this name.

@param indexName the name of the index. If this is null or empty the index named "default" is returned
@return the index best matching the input parameters or the null Index (never null) if none is found
container-search/src/main/java/com/yahoo/prelude/IndexFacts.java