relations property
A map defining all relationships for this entity.
The key is a descriptive name for the relation, and the value is an
instance of a Relation subclass (BelongsTo, HasMany, ManyToMany).
Example:
@override
Map<String, Relation> get relations => {
'author': BelongsTo<User>(this, 'userId'),
};
Implementation
@override
Map<String, Relation> get relations => {};