@Override
  public String toString() {
    return "PropertyUpgradeBehavior{" +
            "add=" + add +
            ", delete=" + delete +
            ", update=" + update +
            '}';
  }
If true, during ambari upgrade property value will be blindly overwritten
with default value
ambari-server/src/main/java/org/apache/ambari/server/state/PropertyUpgradeBehavior.java