src/Forms/TabSet.php
public function insertAfter($insertAfter, $field, $appendIfMissing = true)
    {
        if ($field instanceof Tab || $field instanceof TabSet) {
            $field->setTabSet($this);
        }
        return parent::insertAfter($insertAfter, $field, $appendIfMissing);
    }
public function insertAfter($insertAfter, $field, $appendIfMissing = true)
    {
        if ($field instanceof Tab || $field instanceof TabSet) {
            $field->setTabSet($this);
        }
        return parent::insertAfter($insertAfter, $field, $appendIfMissing);
    }
public function insertAfter ( $ insertAfter , $ field , $ appendIfMissing = true ) { if ( $ field instanceof Tab || $ field instanceof TabSet ) { $ field -> setTabSet ( $ this ) ; } return parent :: insertAfter ( $ insertAfter , $ field , $ appendIfMissing ) ; }
Inserts a field after a particular field in a FieldList.

@param string $insertAfter Name of the field to insert after
@param FormField $field The form field to insert
@return FormField|null
Inserts a field after a particular field in a FieldList .