/**
* Get sub-parameters
*
* @param string $key Name of index or name-encoded parameters array selection, e.g. a.b.c
* @return ParamsInterface Sub-Parameters or empty array() added to tree if not existing
*/
public function subTree($key)
{
$subParametersArray = Get::subTree($this->params, $key);
/** @var self $subTree */
$subTree = new static();
$subTree->setAsReferenceToArray($subParametersArray);
return $subTree;
}
