Method isNested

/**
 * Determine if the field has to be tagnested
 *
 * @return  boolean
 *
 * @since   3.1
 */
public function isNested()
{
    if ($this->isNested === null) {
        // If mode="nested" || ( mode not set & config = nested )
        if (isset($this->element['mode']) && (string) $this->element['mode'] === 'nested' || !isset($this->element['mode']) && $this->comParams->get('tag_field_ajax_mode', 1) == 0) {
            $this->isNested = true;
        }
    }
    return $this->isNested;
}