private function createRelationship($property, array $column_schema)
{
$assoc = $this->getNode($column_schema, Schema::REL_ASSOCIATION, true);
$relationship = new Relationship($property, RelationshipType::memberByValue($assoc));
$relationship->setTarget($this->getNode($column_schema, Schema::REL_TARGET, true))->setInversedBy($this->getNode($column_schema, Schema::REL_INVERSED_BY, false))->setGetter($this->getNode($column_schema, Schema::GETTER, false))->setSetter($this->getNode($column_schema, Schema::SETTER, false))->setSortableBy($this->createSortables($column_schema));
return $relationship;
}