code: function getUserMetadataFileName(options, user) {
  	let userId;
  	if(typeof user === "string") {
  		userId = user;
  	} else if(user && typeof user.username === 'string') {
  		userId = user.username;
  	} else {
  		return null;
  	}
  	return nodePath.join(getUserRootLocation(options, userId), FILENAME_USER_METADATA);
  }
docs: Returns the fully qualified file path of the metadata for the given user. Returns null if no user
  is provided
  @param {{?}} options The options map
  @param {string|{?}} user The user id or map of user options