is::calculateLags

protected function calculateLags()
{
	if(is_array($this->relations))
	{
		foreach($this->relations as $parent => &$level)
		{
			if(is_array($level))
			{
				foreach($level as $id => &$rel)
				{
					$this->updateLag($rel);
				}
				unset($rel);
			}
		}
		unset($level);
	}
}