getFieldStoragesByModule example

public function __construct(EntityTypeManagerInterface $entity_type_manager, TranslationInterface $string_translation, FieldTypePluginManagerInterface $field_type_manager) {
    $this->fieldStorageConfigStorage = $entity_type_manager->getStorage('field_storage_config');
    $this->stringTranslation = $string_translation;
    $this->fieldTypeManager = $field_type_manager;
  }

  /** * {@inheritdoc} */
  public function validate($module) {
    $reasons = [];
    if ($field_storages = $this->getFieldStoragesByModule($module)) {
      // Provide an explanation message (only mention pending deletions if there       // remain no actual, non-deleted fields.)       $fields_in_use = [];
      foreach ($field_storages as $field_storage) {
        if (!$field_storage->isDeleted()) {
          $fields_in_use[$field_storage->getType()][] = $field_storage->getLabel();
        }
      }
      if (!empty($fields_in_use)) {
        foreach ($fields_in_use as $field_type => $field_storages) {
          $field_type_label = $this->getFieldTypeLabel($field_type);