The submit callback to cancel the paragraphs conversion.
public static function paragraphsConvertCancel(array $form, FormStateInterface $form_state) {
$submit = ParagraphsWidget::getSubmitElementInfo($form, $form_state, ParagraphsWidget::ACTION_POSITION_HEADER);
$new_mode = $submit['button']['#paragraphs_mode'];
if ($new_mode === 'edit') {
$submit['widget_state'] = static::autocollapse($submit['widget_state']);
}
$submit['widget_state']['paragraphs'][$submit['button']['#delta']]['mode'] = $new_mode;
if (!empty($submit['button']['#paragraphs_show_warning'])) {
$submit['widget_state']['paragraphs'][$submit['button']['#delta']]['show_warning'] = $submit['button']['#paragraphs_show_warning'];
}
static::setWidgetState($submit['parents'], $submit['field_name'], $form_state, $submit['widget_state']);
$form_state
->setRebuild();
}