The IJesPanel is shared by JesWidget, JesScreen,
and numerous JES parts. It defines the methods that must be made
available if the object is capable of being combined with other
objects to form new JES widgets.
Produce an AttributeTable holding the names and values of fields.
The difference with getValue() is that this method is not
used to provide programmatic processing of the values. It is
used by those widgets that can embed screens and JesPanels for
internal processing of those embedded screens and panels.
All widgets should implement this method to produce the fields
names and values (if any) that they manage.