     #if os(iOS)
     public func authorize(withCallback callbackURL: URL,
 						  presentingFrom presenting: UIViewController?,
+						  forceLogin: Bool = false,
 						  success: TokenSuccessHandler?,
 						  failure: FailureHandler? = nil) {
         self.postOAuthRequestToken(with: callbackURL, success: { token, response in

                    success?(accessToken!, response)
                    }, failure: failure)
            }
            
            let authorizeURL = URL(string: "oauth/authorize", relativeTo: TwitterURL.oauth.url)
            let queryURL = URL(string: authorizeURL!.absoluteString + "?oauth_token=\(token!.key)")!
            NSWorkspace.shared.open(queryURL)
        }, failure: failure)
    }

                    success?(accessToken!, response)
                    }, failure: failure)
            }
			
			let forceLogin = forceLogin ? "&force_login=true" : ""
			let query = "oauth/authorize?oauth_token=\(token!.key)\(forceLogin)"
            let queryUrl = URL(string: query, relativeTo: TwitterURL.oauth.url)!
			
            if #available(iOS 9.0, *) , let delegate = presenting as? SFSafariViewControllerDelegate {
                let safariView = SFSafariViewController(url: queryUrl)
                safariView.delegate = delegate
