gistfile1.txt

  func encode(apiKey: String) throws -> String {
        guard let apiKeyData = "api:\(apiKey)".data(using: .utf8) else {
            throw Error.encodingProblem
        }
        let authKey = apiKeyData.base64EncodedData()
        guard let authKeyEncoded = String.init(data: authKey, encoding: .utf8) else {
            throw Error.encodingProblem
        }
        
        return authKeyEncoded
    }