private boolean specifiesUniqueResource(Predicate predicate) {
    SimplifyingPredicateVisitor visitor = new SimplifyingPredicateVisitor(this);
    PredicateHelper.visit(predicate, visitor);
    List<Predicate> predicates = visitor.getSimplifiedPredicates();

    return predicates.size() == 1 && PredicateHelper.getPropertyIds(predicate).containsAll(getPKPropertyIds());
  }
Helper method to get a configuration request, if one exists.
@param parentCategory  the parent category name.  Checks for a property
   whose category is the parent and marked as a desired config.
@param properties  the properties on the request.
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/AbstractResourceProvider.java