private static boolean inclusiveWithin(int x, int low, int high) {
        return low <= x && x <= high;
    }
Returns the path to the given xml node, where each node name is separated by the given separator string.

@param n the xml node to find path to
@param sep the separator string
@return the path to the xml node as a String
vespajlib/src/main/java/com/yahoo/text/XML.java