_getAssetPath(asset) {
    /* @type {String} */
    let assetPath;

    if (typeof asset !== 'object') {
      assetPath = asset;
    } else if (this.env in asset) {
      assetPath = asset[this.env];
    } else {
      assetPath = asset.development;
    }

    if (!assetPath) {
      return;
    }

    assetPath = assetPath.split('\\').join('/');

    if (assetPath.split('/').length < 2) {
      console.log(
        chalk.red(
          `Using \`app.import\` with a file in the root of \`vendor/\` causes a significant performance penalty. Please move \`${assetPath}\` into a subdirectory.`
        )
      );
    }

    if (/[*,]/.test(assetPath)) {
      throw new Error(
        `You must pass a file path (without glob pattern) to \`app.import\`.  path was: \`${assetPath}\``
      );
    }

    return assetPath;
  }
@private
    @method _getAssetPath
    @param {(Object|String)} asset
    @return {(String|undefined)} assetPath