EntityFormDisplay::processForm

public EntityFormDisplay::processForm($element, FormStateInterface $form_state, $form)

public function processForm($element, FormStateInterface $form_state, $form) {
  // Assign the weights configured in the form display.
  foreach ($this->getComponents() as $name => $options) {
    if (isset($element[$name])) {
      $element[$name]['#weight'] = $options['weight'];
    }
  }

  // Hide extra fields.
  $extra_fields = \Drupal::entityManager()->getExtraFields($this->targetEntityType, $this->bundle);
  $extra_fields = isset($extra_fields['form']) ? $extra_fields['form'] : array();
  foreach ($extra_fields as $extra_field => $info) {
    if (!$this->getComponent($extra_field)) {
      $element[$extra_field]['#access'] = FALSE;
    }
  }
  return $element;
}