         state = .Running
     }
 
+    /**
+     Stops monitoring the heart rate.
+
+     - throws: A `BoumBoumError` if something fails.
+     */
     public func stopMonitoring() throws {
         //Ensuring we have a camera
         guard let camera = camera else {

import UIKit
import AVFoundation

public enum BoumBoumError: ErrorType {
    case AlreadyRunning
    case AlreadyStopped

    // MARK: Start / Stop
    ////////////////////////////////////////////////////////////////////////////

    /**
    Starts monitoring the heart rate.

    - throws: A `BoumBoumError` if something fails.
    */
    public func startMonitoring() throws {
        //Ensuring we have a camera
        guard let camera = camera else {
