@Override
  public Object getPropertyValue(String id) {
    String categoryKey = getCategoryKey(PropertyHelper.getPropertyCategory(id));

    Map<String, Object> properties = propertiesMap.get(categoryKey);

    return properties == null ?
        null : properties.get(PropertyHelper.getPropertyName(id));
  }
Construct a resource from the given resource, setting only the properties
that are found in the given set of property and category ids.

@param resource    the resource to copy
@param propertyIds the set of requested property and category ids
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/ResourceImpl.java