private static Pair<String, String> halveAt(char divider, String string) {
        int pos = string.indexOf(divider);
        if (pos >= 0) {
            return new Pair<>(string.substring(0, pos), string.substring(pos + 1));
        }
        return new Pair<>(string, "");
    }
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