How to use the netlify-cms-lib-util.EditorialWorkflowError function in netlify-cms-lib-util

unpublishedEntry(collection, slug) {
    const entry = window.repoFilesUnpublished.find(
      e => e.metaData.collection === collection.get('name') && e.slug === slug,
    );
    if (!entry) {
      return Promise.reject(
        new EditorialWorkflowError('content is not under editorial workflow', true),
      );
    }
    entry.mediaFiles = this.getMediaFiles(entry);

    return Promise.resolve(entry);
  }

}).catch(() => {
      throw new EditorialWorkflowError('content is not under editorial workflow', true);
    });
  }

baseOwner,
          baseRepoName,
          baseExpression: `${this.branch}:${path}`,
        },
      });
      if (!data.head.object) {
        throw new EditorialWorkflowError('content is not under editorial workflow', true);
      }
      const result = {
        metaData,
        fileData: data.head.object.text,
        isModification: !!data.base.object,
      };
      return result;
    } else {
      throw new EditorialWorkflowError('content is not under editorial workflow', true);
    }
  }

}).catch(() => {
      throw new EditorialWorkflowError('content is not under editorial workflow', true);
    });
  }