Type "ForecastAPIClient" not conformingto protocol "APICLient"

I had the same problem, so I went through all my code vs the download code with a fine tooth comb and found that in the protocol APIClient, I had a line: init(config: NSURLSessionConfiguration) and the download code did not. I deleted this line, and the error went away.

BEFORE: protocol APIClient { var configuration: NSURLSessionConfiguration { get } var session: NSURLSession { get }

 init(config: NSURLSessionConfiguration) 

func JSONTaskWithRequest(request: NSURLRequest, completion: JSONTaskCompletion) -> JSONTask
func fetch<T: JSONDecodable>(request: NSURLRequest, parse: JSON -> T?, completion: APIResult<T> -> Void)

}

AFTER: protocol APIClient { var configuration: NSURLSessionConfiguration { get } var session: NSURLSession { get }

func JSONTaskWithRequest(request: NSURLRequest, completion: JSONTaskCompletion) -> JSONTask
func fetch<T: JSONDecodable>(request: NSURLRequest, parse: JSON -> T?, completion: APIResult<T> -> Void)

}

In my code, I forgot to add protocol conformance to T in fetch method in the protocol declaration (only added this bit to the default implementation which meant that those two methods weren't the same and so ForecastAPIClient was missing fetch method)

protocol APIClient {
   ...
   func fetch<T: JSONDecodable>( ...

Richard Ni were you able to find an answer to this problem? I'm having the same issue, and when I run the program the compiler is telling me is that the ForecastAPIClient is not conforming to the APIClient because I do not have an implementation of this method:

func JSONTaskWithRequest(request: URLRequest, completion: JSONTaskCompletion) -> JSONTask

I've ran through the videos up and down, and am not getting close to the answer. I thought the fetch method handled this task...