MissingDependencyException example

// We can find the unmet module dependencies by finding the module         // machine names keys that are not in $installed_modules keys.         $unmet_module_dependencies = array_diff_key($module_dependencies, $installed_modules);

        if ($theme_data[$theme]->info[ExtensionLifecycle::LIFECYCLE_IDENTIFIER] === ExtensionLifecycle::DEPRECATED) {
          @trigger_error("The theme '$theme' is deprecated. See " . $theme_data[$theme]->info['lifecycle_link'], E_USER_DEPRECATED);
        }

        // Prevent themes with unmet module dependencies from being installed.         if (!empty($unmet_module_dependencies)) {
          $unmet_module_dependencies_list = implode(', ', array_keys($unmet_module_dependencies));
          throw new MissingDependencyException("Unable to install theme: '$theme' due to unmet module dependencies: '$unmet_module_dependencies_list'.");
        }

        foreach ($module_dependencies as $dependency => $dependency_object) {
          if ($incompatible = $this->checkDependencyMessage($module_list, $dependency, $dependency_object)) {
            $sanitized_message = Html::decodeEntities(strip_tags($incompatible));
            throw new MissingDependencyException("Unable to install theme: $sanitized_message");
          }
        }

        // Add dependencies to the list of themes to install. The new themes         // will be processed as the parent foreach loop continues.

  public function install(array $module_list, $enable_dependencies = TRUE) {
    $extension_config = \Drupal::configFactory()->getEditable('core.extension');
    // Get all module data so we can find dependencies and sort and find the     // core requirements. The module list needs to be reset so that it can     // re-scan and include any new modules that may have been added directly     // into the filesystem.     $module_data = \Drupal::service('extension.list.module')->reset()->getList();
    foreach ($module_list as $module) {
      if (!empty($module_data[$module]->info['core_incompatible'])) {
        throw new MissingDependencyException("Unable to install modules: module '$module' is incompatible with this version of Drupal core.");
      }
      if ($module_data[$module]->info[ExtensionLifecycle::LIFECYCLE_IDENTIFIER] === ExtensionLifecycle::OBSOLETE) {
        throw new ObsoleteExtensionException("Unable to install modules: module '$module' is obsolete.");
      }
      if ($module_data[$module]->info[ExtensionLifecycle::LIFECYCLE_IDENTIFIER] === ExtensionLifecycle::DEPRECATED) {
        @trigger_error("The module '$module' is deprecated. See " . $module_data[$module]->info['lifecycle_link'], E_USER_DEPRECATED);
      }
    }
    if ($enable_dependencies) {
      $module_list = $module_list ? array_combine($module_list, $module_list) : [];
      if ($missing_modules = array_diff_key($module_list, $module_data)) {