public static function fromDataMap( $dataMap )
    {
        $set = new ezpContentFieldSet();
        foreach( $dataMap as $attribute )
        {
            $identifier = $attribute->attribute( 'contentclass_attribute_identifier' );
            $set->fields[$identifier] = ezpContentField::fromContentObjectAttribute( $attribute );
        }
        $set->initIterator();
        return $set;
    }