code: function wrapError(err) {
  	if (err && !(err instanceof gutil.PluginError)) {
  		err = new PluginError(err.plugin || PLUGIN_NAME, err, {
  			showStack: (err.showStack !== false)
  		});
  	}
  	return err;
  }
docs: Ensure that error is wrapped in a gulp PluginError
  
  @param {Object} err - An error to be wrapped
  @returns {Object} A wrapped error