getDisplayStatuses example

// Only show the settings if there is at least one custom display mode.       $display_mode_options = $this->getDisplayModeOptions();
      // Unset default option.       unset($display_mode_options['default']);
      if ($display_mode_options) {
        $form['modes'] = [
          '#type' => 'details',
          '#title' => $this->t('Custom display settings'),
        ];
        // Prepare default values for the 'Custom display settings' checkboxes.         $default = [];
        if ($enabled_displays = array_filter($this->getDisplayStatuses())) {
          $default = array_keys(array_intersect_key($display_mode_options, $enabled_displays));
        }
        natcasesort($display_mode_options);
        $form['modes']['display_modes_custom'] = [
          '#type' => 'checkboxes',
          '#title' => $this->t('Use custom display settings for the following @display_context modes', ['@display_context' => $this->displayContext]),
          '#options' => $display_mode_options,
          '#default_value' => $default,
        ];
        // Provide link to manage display modes.         $form['modes']['display_modes_link'] = $this->getDisplayModesLink();
      }