protected function _get_instances($rows)
{
$size = count($rows);
$instances = array();
for ($i = 0; $i < $size; $i++) {
$row = $this->_create_instance_from_row($rows[$i]);
$key = isset($row->{$this->_instance_id_column}) && $this->_associative_results ? $row->id() : $i;
$instances[$key] = $row;
}
return $instances;
}