EntityRequisite::exists

public function exists($id)
{
	$id = (int)$id;
	if ($id <= 0)
		return false;

	$row = $this->getList(
		array(
			'filter' => array('=ID' => $id),
			'select' => array('ID'),
			'limit' => 1
		)
	)->fetch();

	if (!is_array($row))
		return false;

	return true;
}