// that issue.
if ($this->getRequest()->get('immutable')) {
$form_state->addBuildInfo('immutable', TRUE);
- if ($this->getRequest()->get('cache') && $this->getRequest()->isMethodSafe()) {
+ if ($this->getRequest()->get('cache') && $this->getRequest()->isMethodCacheable()) {
$form_state->setRequestMethod('FAKE');
$form_state->setCached();
}