/**
* Propel uses for his nested-set objects `lft` and `rgt` fields.
* So we include with this condition all entries 'inside' the entry
* defined through $condition.
*
* @param Condition $condition
* @return Condition
*/
public function getNestedSubCondition(Condition $condition)
{
$result = new Condition(null, $this->jarves);
$sub = new ConditionSubSelect(null, $this->jarves);
$sub->select('sub.lft');
$sub->addSelfJoin('sub', 'sub.lft BETWEEN %table%.lft+1 AND %table%.rgt-1');
$sub->setRules($condition->getRules());
$subCondition = new Condition();
$subCondition->addAnd(['lft', 'IN', $sub]);
$result->addAnd($subCondition);
return $result;
}