* @param rd the recursion depth of directory from the root
* @param fd the fetch depth = number of parents fetched
*/
public void genericTestForSingleValuedRecursiveField(String plan, int rd,
int fd) {
PCDirectory result = queryDirectoryWithPlan(plan, rd, fd);
checkParents(result, rd, fd);
Object children = PCDirectory.reflect(result, "_children");
assertNull(children);