Example:
A team has many players (or rather, each player has exactly one team).
Each player has exactly one nationality.
Is there a built-in function to easily query all nationalities of one team?
Something like
DataObject::get_one('Team', 'Tiny Giants')->Players()->Nationalities();
or
DataObject::get_one('Team', 'Tiny Giants')->Nationalities(); // this is, BTW, RoR syntax for has_many :through