writeCache(loader, options, manifestContents) {
    const manifestName = options.manifest || 'fbp.json';
    const filePath = path.resolve(loader.baseDir, manifestName);

    return writeFile(filePath, JSON.stringify(manifestContents, null, 2), {
      encoding: 'utf-8',
    })
      .then(() => manifestContents);
  }
@param {import("../ComponentLoader").ComponentLoader} loader
@param {import("fbp-manifest/dist/lib/list").FbpManifestOptions} options
@param {Object} manifestContents
@param {import("fbp-manifest/src/lib/list").FbpManifestDocument} manifestContents
@returns {Promise<import("fbp-manifest/dist/lib/list").FbpManifestDocument>}