@Override
        public String toString() {
            if (from + 1 == to) {
                return Integer.toString(from);
            } else {
                return "[" + from + "," + to + ">";
            }
        }
Parses a search path and select nodes from the given cluster based on it.

@param searchPath unparsed search path expression (see: model.searchPath in Search API reference)
@param cluster the search cluster from which nodes are selected
@throws InvalidSearchPathException if the searchPath is malformed
@return list of nodes chosen with the search path, or an empty list in which
        case some other node selection logic should be used
container-search/src/main/java/com/yahoo/search/dispatch/SearchPath.java