Flattened Relationships  ObjRelationships that map to more than
a single DbRelationship are called "flattened".  The most common
case for using flattened relationships is modeling many-to-many
relationships with a join table. E.g. ARTIST DbEntity has to-
many relationship to ARTIST_EXHIBIT; ARTIST_EXHIBIT in turn has
a to-one relationship to EXHIBIT DbEntity. We can create a
single ObjRelationship from Artist ObjEntity to Exhibit
ObjEntity that spawns two DbRelationships. This will be a to-
many relationship. Lets say it is called "exhibitArray".
Generated class file for Artist would contain a
getExhibitArray() method returning a list of Exhibits for a
given artist instance. An obvious advantage of having a
flattened relationship in this case is to avoid mapping a join
table as an object, meaningless in the context of the object
model.  Flattened relationships work across any combination of
to-one and to-many DbRelationships. If all the relationships are
to-one, then the resulting flattened relationship is also