.h

@interface ICSessionManager (CheckAPI)

- (nullable NSURLSessionDataTask *)checkAPIConnection:(nullable void (^)(void))successBlock
                                              failure:(nullable void (^)(NSURLSessionDataTask * _Nullable task, NSError *error))failureBlock;

@end


.m
@implementation ICSessionManager (CheckAPI)

- (nullable NSURLSessionDataTask *)checkAPIConnection:(nullable void (^)(void))successBlock
                                           failure:(nullable void (^)(NSURLSessionDataTask * _Nullable task, NSError *error))failureBlock {

  return [self GET:ICTestAPI
        parameters:nil
           success:^( NSURLSessionDataTask * _Nullable task, id responseObject) {
               if (successBlock) {
                 dispatch_async(dispatch_get_main_queue(), ^{
                   successBlock();
                 });
               }
           } failure:[ICSessionManager forwardFailureBlock:failureBlock]];
}

@end