The theme manager. Type:

protected FormBuilder::handleInputElement($form_id, &$element, FormStateInterface

The current user. Type:

public FormBuilder::executeValidateHandlers(&$form, FormStateInterface

public FormBuilder::doSubmitForm(&$form, FormStateInterface &$form_state)

public FormBuilder::doBuildForm($form_id, &$element, FormStateInterface

public FormBuilder::getCache($form_build_id, FormStateInterface $form_state)

The element info manager. Type:

protected FormBuilder::buttonWasClicked($element, FormStateInterface &$

Type: