Represents a subset of the cmp and cmr-fields of a bean. Related fields in a bean can be put into groups which are faulted into memory together as a unit. A group can be associated with a query or relationship, so that when a bean is loaded as the result of executing a query or following a relationship, only the fields mentioned in the group are loaded.
A special group named default is used for queries and relationships that have no group specified. By default, the default group contains all of a bean's cmp-fields and any cmr-fields that add a foreign key to the persistent state of the bean.
A field may belong to multiple groups. In this case, the getXXX() method for the field will fault in the first group (lexically speaking) that contains the field.
