registerRelationSchema method
Registers a relational entity's schema in DatumRelationSchema the first time an instance is seen, enabling instance-free relation traversal (#21).
Implementation
void registerRelationSchema(DatumEntityInterface entity) {
if (entity is RelationalDatumEntity && !DatumRelationSchema.isRegistered(entity.runtimeType)) {
DatumRelationSchema.register(entity.runtimeType, entity.relationSchema);
}
}