• getAttribute(String name): returns the value of the attribute identified by the given name, or null if the name does not correspond to any attribute. • removeAttribute(String name): removes the attribute it’s identified by an unique id which can be read calling the getId() method. This value will be null if the session is temporary. Although Wicket is able to automatically recognize when it needs to the contained object, if it is not null. If the predicate doesn’t evaluate to true, the contained object will be null. Example: //the filtered model will have a null model object if person's name //is

• getAttribute(String name): returns the value of the attribute identified by the given name, or null if the name does not correspond to any attribute. • removeAttribute(String name): removes the attribute it’s identified by an unique id which can be read calling the getId() method. This value will be null if the session is temporary. Although Wicket is able to automatically recognize when it needs to the contained object, if it is not null. If the predicate doesn’t evaluate to true, the contained object will be null. Example: //the filtered model will have a null model object if person's name //is

• getAttribute(String name): returns the value of the attribute identified by the given name, or null if the name does not correspond to any attribute. • removeAttribute(String name): removes the attribute it’s identified by an unique id which can be read calling the getId() method. This value will be null if the session is temporary. Although Wicket is able to automatically recognize when it needs to the contained object, if it is not null. If the predicate doesn’t evaluate to true, the contained object will be null. Example: //the filtered model will have a null model object if person's name //is

getAttribute(String name): returns the value of the attribute identified by the given name, or 56 null if the name does not correspond to any attribute. • removeAttribute(String name): removes the attribute it’s identified by an unique id which can be read calling the getId() method. This value will be null if the session is temporary. Although Wicket is able to automatically recognize when it needs to PropertyModel(person, "spouse.name"));  PropertyModel is null-safe, which means we don’t have to worry if property expression includes a null value in its path. If such a value is encountered, an empty