@Override
  public void acceptComparisonPredicate(ComparisonPredicate predicate) {
    properties.put(predicate.getPropertyId(), predicate.getValue());
  }
Predicate visitor for extracting property values from the {@link PropertyPredicate}s of a predicate graph.
ambari-server/src/main/java/org/apache/ambari/server/controller/internal/PropertyPredicateVisitor.java