Saves an object in this session, using the name specified. If an object of the same name already exists, the object is replaced.
If the value passed in is null, this has the same effect as calling removeAttribute().
Note that getAttribute() returns the state of the object at the time of calling this method, any changes made to the saved object after calling this method
will not be reflected in the object returned by getAttribute().
Note that getAttribute() returns the state of the object at the time of calling this method, any changes made to the saved object after calling this method will not be reflected in the object returned by getAttribute().