@Override
  public Set<Resource> populateResources(Set<Resource> resources,
               Request request, Predicate predicate) throws SystemException {

    Set<Resource> keepers = new HashSet<>();
    for (Resource resource : resources) {
      populateResource(resource, request, predicate);
      keepers.add(resource);
    }
    return keepers;
  }
Support properties with aggregate functions and metrics padding method.
ambari-server/src/main/java/org/apache/ambari/server/controller/metrics/timeline/AMSReportPropertyProvider.java