   // MARK: - Private state
 
   /**
-   MCNearbyServiceAdvertiser object .
+   MCNearbyServiceAdvertiser object.
    */
   private let advertiser: MCNearbyServiceAdvertiser
 

       3. *Must* contain at least one ASCII letter
       4. *Must* not begin or end with a hyphen
       5. Hyphens must not be adjacent to other hyphens
       For more details, see [RFC6335](https://tools.ietf.org/html/rfc6335#section-5.1).

     - receivedInvitation:

  // MARK: - Internal state

  /**
   Bool flag indicates if `Advertiser` object is advertising.
   */
  internal private(set) var advertising: Bool = false

